fix(fpga): harden XDC constraints + anchor ADC overflow/clock-tap pins

XDC (xc7a50t_ftg256.xdc): - Tighten FT2232H set_input_delay -min from 0.0 -> 1.0 ns (Tco_min + trace_min estimate; 0.0 was unrealistic and under-constrained hold). - Tighten FT2232H set_output_delay -max from 11.667 -> 5.5 ns (Tsu_FT ~5 ns + trace_max; previous value budgeted the full 16.67 ns period). - Replace pairwise 'set_false_path -from CLK -to CLK' CDC waivers with 'set_clock_groups -asynchronous' for the four domain pairs: clk_100m <-> adc_dco_p, clk_100m <-> clk_120m_dac, clk_100m <-> ft_clkout, clk_120m_dac <-> ft_clkout. Rationale: clock-groups is the idiomatic SDC form. Pairwise false_path is over-broad and masks inadvertent unrelated CDCs introduced in future PRs. Narrow register-level false_path on reset_sync_reg[*] is kept. radar_system_top_50t.v: - Add top-level differential input ports adc_or_p/n (AD9484 overflow flag, pads M6/N6) and fpga_adc_clock_p/n (AD9523->ADC sample clock tap, pads N11/N12, input-only to avoid contention with AD9523 driver). - Anchor both via IBUFDS (DIFF_TERM=TRUE, IOSTANDARD=LVDS_25) wrapped in (* DONT_TOUCH = "TRUE" *) so synthesis cannot strip the ports. - Buffered nets (adc_or_buf, fpga_adc_clock_buf) are intentionally unconsumed pending a follow-up PR that wires adc_or_buf into the receive-path status flags (issue: numeric-saturation visibility to MCU) and decides whether fpga_adc_clock_buf is diagnostic-only or feeds an MMCM (in which case the buffer will need to move to a clock-capable path). Not validated locally: no Verilator / Vivado on the dev host. Requires report_timing_summary and report_cdc on the remote Vivado 2025.2 host before bitstream release.
Merge pull request #113 from NawfalMotii79/fix/adar1000-channel-rotation
2026-04-19 19:29:10 +05:45 · 2026-04-19 14:05:50 +03:00 · 2026-04-19 16:28:07 +05:45 · 2026-04-18 20:34:52 +05:45 · 2026-04-18 16:46:30 +03:00 · 2026-04-18 10:51:36 +03:00
51 changed files with 12007 additions and 8731 deletions
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@@ -18,7 +18,7 @@ ADAR1000_AGC::ADAR1000_AGC()
    , min_gain(0)
    , max_gain(127)
    , holdoff_frames(4)
-    , enabled(true)
+    , enabled(false)
    , holdoff_counter(0)
    , last_saturated(false)
    , saturation_event_count(0)
@@ -20,18 +20,71 @@ static const struct {
    {ADAR_4_CS_3V3_GPIO_Port, ADAR_4_CS_3V3_Pin}  // ADAR1000 #4
 };

-// Vector Modulator lookup tables
+// ADAR1000 Vector Modulator lookup tables (128-state phase grid, 2.8125 deg step).
+//
+// Source: Analog Devices ADAR1000 datasheet Rev. B, Tables 13-16, page 34
+//   (7_Components Datasheets and Application notes/ADAR1000.pdf)
+// Cross-checked against the ADI Linux mainline driver (GPL-2.0, NOT vendored):
+//   https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/
+//     drivers/iio/beamformer/adar1000.c  (adar1000_phase_values[])
+// The 128 byte values themselves are factual data from the datasheet and are
+// not subject to copyright; only the ADI driver code is GPL.
+//
+// Byte format (per datasheet):
+//   bit  [7:6] reserved (0)
+//   bit  [5]   polarity:  1 = positive lobe (sign(I) or sign(Q) >= 0)
+//                          0 = negative lobe
+//   bits [4:0] 5-bit unsigned magnitude (0..31)
+// At magnitude=0 the polarity bit is physically meaningless; the datasheet
+// uses POL=1 (e.g. VM_Q at 0 deg = 0x20, VM_I at 90 deg = 0x21).
+//
+// Index mapping is uniform: VM_I[k] / VM_Q[k] correspond to phase angle
+// k * 360/128 = k * 2.8125 degrees.  Callers index as VM_*[phase % 128].
 const uint8_t ADAR1000Manager::VM_I[128] = {
-    // ... (same as in your original file)
+    0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3E, 0x3E, 0x3D,  // [  0]   0.0000 deg
+    0x3D, 0x3C, 0x3C, 0x3B, 0x3A, 0x39, 0x38, 0x37,  // [  8]  22.5000 deg
+    0x36, 0x35, 0x34, 0x33, 0x32, 0x30, 0x2F, 0x2E,  // [ 16]  45.0000 deg
+    0x2C, 0x2B, 0x2A, 0x28, 0x27, 0x25, 0x24, 0x22,  // [ 24]  67.5000 deg
+    0x21, 0x01, 0x03, 0x04, 0x06, 0x07, 0x08, 0x0A,  // [ 32]  90.0000 deg
+    0x0B, 0x0D, 0x0E, 0x0F, 0x11, 0x12, 0x13, 0x14,  // [ 40] 112.5000 deg
+    0x16, 0x17, 0x18, 0x19, 0x19, 0x1A, 0x1B, 0x1C,  // [ 48] 135.0000 deg
+    0x1C, 0x1D, 0x1E, 0x1E, 0x1E, 0x1F, 0x1F, 0x1F,  // [ 56] 157.5000 deg
+    0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1E, 0x1E, 0x1D,  // [ 64] 180.0000 deg
+    0x1D, 0x1C, 0x1C, 0x1B, 0x1A, 0x19, 0x18, 0x17,  // [ 72] 202.5000 deg
+    0x16, 0x15, 0x14, 0x13, 0x12, 0x10, 0x0F, 0x0E,  // [ 80] 225.0000 deg
+    0x0C, 0x0B, 0x0A, 0x08, 0x07, 0x05, 0x04, 0x02,  // [ 88] 247.5000 deg
+    0x01, 0x21, 0x23, 0x24, 0x26, 0x27, 0x28, 0x2A,  // [ 96] 270.0000 deg
+    0x2B, 0x2D, 0x2E, 0x2F, 0x31, 0x32, 0x33, 0x34,  // [104] 292.5000 deg
+    0x36, 0x37, 0x38, 0x39, 0x39, 0x3A, 0x3B, 0x3C,  // [112] 315.0000 deg
+    0x3C, 0x3D, 0x3E, 0x3E, 0x3E, 0x3F, 0x3F, 0x3F,  // [120] 337.5000 deg
 };

 const uint8_t ADAR1000Manager::VM_Q[128] = {
-    // ... (same as in your original file)
+    0x20, 0x21, 0x23, 0x24, 0x26, 0x27, 0x28, 0x2A,  // [  0]   0.0000 deg
+    0x2B, 0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x33, 0x34,  // [  8]  22.5000 deg
+    0x35, 0x36, 0x37, 0x38, 0x38, 0x39, 0x3A, 0x3A,  // [ 16]  45.0000 deg
+    0x3B, 0x3C, 0x3C, 0x3C, 0x3D, 0x3D, 0x3D, 0x3D,  // [ 24]  67.5000 deg
+    0x3D, 0x3D, 0x3D, 0x3D, 0x3D, 0x3C, 0x3C, 0x3C,  // [ 32]  90.0000 deg
+    0x3B, 0x3A, 0x3A, 0x39, 0x38, 0x38, 0x37, 0x36,  // [ 40] 112.5000 deg
+    0x35, 0x34, 0x33, 0x31, 0x30, 0x2F, 0x2E, 0x2D,  // [ 48] 135.0000 deg
+    0x2B, 0x2A, 0x28, 0x27, 0x26, 0x24, 0x23, 0x21,  // [ 56] 157.5000 deg
+    0x20, 0x01, 0x03, 0x04, 0x06, 0x07, 0x08, 0x0A,  // [ 64] 180.0000 deg
+    0x0B, 0x0D, 0x0E, 0x0F, 0x10, 0x11, 0x13, 0x14,  // [ 72] 202.5000 deg
+    0x15, 0x16, 0x17, 0x18, 0x18, 0x19, 0x1A, 0x1A,  // [ 80] 225.0000 deg
+    0x1B, 0x1C, 0x1C, 0x1C, 0x1D, 0x1D, 0x1D, 0x1D,  // [ 88] 247.5000 deg
+    0x1D, 0x1D, 0x1D, 0x1D, 0x1D, 0x1C, 0x1C, 0x1C,  // [ 96] 270.0000 deg
+    0x1B, 0x1A, 0x1A, 0x19, 0x18, 0x18, 0x17, 0x16,  // [104] 292.5000 deg
+    0x15, 0x14, 0x13, 0x11, 0x10, 0x0F, 0x0E, 0x0D,  // [112] 315.0000 deg
+    0x0B, 0x0A, 0x08, 0x07, 0x06, 0x04, 0x03, 0x01,  // [120] 337.5000 deg
 };

-const uint8_t ADAR1000Manager::VM_GAIN[128] = {
-    // ... (same as in your original file)
-};
+// NOTE: a VM_GAIN[128] table previously existed here as a placeholder but was
+// never populated and never read.  The ADAR1000 vector modulator has no
+// separate gain register: phase-state magnitude is encoded directly in
+// bits [4:0] of the VM_I/VM_Q bytes above.  Per-channel VGA gain is a
+// distinct register (CHx_RX_GAIN at 0x10-0x13, CHx_TX_GAIN at 0x1C-0x1F)
+// written with the user-supplied byte directly by adarSetRxVgaGain() /
+// adarSetTxVgaGain().  Do not reintroduce a VM_GAIN[] array.

 ADAR1000Manager::ADAR1000Manager() {
    for (int i = 0; i < 4; ++i) {
@@ -815,11 +868,22 @@ void ADAR1000Manager::adarSetRamBypass(uint8_t deviceIndex, uint8_t broadcast) {
 }

 void ADAR1000Manager::adarSetRxPhase(uint8_t deviceIndex, uint8_t channel, uint8_t phase, uint8_t broadcast) {
+    // channel is 1-based (CH1..CH4) per API contract documented in
+    // ADAR1000_AGC.cpp and matching ADI datasheet terminology.
+    // Reject out-of-range early so a stale 0-based caller does not
+    // silently wrap to ((0-1) & 0x03) == 3 and write to CH4.
+    // See issue #90.
+    if (channel < 1 || channel > 4) {
+        DIAG("BF", "adarSetRxPhase: channel %u out of range [1..4], ignored", channel);
+        return;
+    }
    uint8_t i_val = VM_I[phase % 128];
    uint8_t q_val = VM_Q[phase % 128];

-    uint32_t mem_addr_i = REG_CH1_RX_PHS_I + (channel & 0x03) * 2;
-    uint32_t mem_addr_q = REG_CH1_RX_PHS_Q + (channel & 0x03) * 2;
+    // Subtract 1 to convert 1-based channel to 0-based register offset
+    // before masking. See issue #90.
+    uint32_t mem_addr_i = REG_CH1_RX_PHS_I + ((channel - 1) & 0x03) * 2;
+    uint32_t mem_addr_q = REG_CH1_RX_PHS_Q + ((channel - 1) & 0x03) * 2;

    adarWrite(deviceIndex, mem_addr_i, i_val, broadcast);
    adarWrite(deviceIndex, mem_addr_q, q_val, broadcast);
@@ -827,11 +891,16 @@ void ADAR1000Manager::adarSetRxPhase(uint8_t deviceIndex, uint8_t channel, uint8
 }

 void ADAR1000Manager::adarSetTxPhase(uint8_t deviceIndex, uint8_t channel, uint8_t phase, uint8_t broadcast) {
+    // channel is 1-based (CH1..CH4). See issue #90.
+    if (channel < 1 || channel > 4) {
+        DIAG("BF", "adarSetTxPhase: channel %u out of range [1..4], ignored", channel);
+        return;
+    }
    uint8_t i_val = VM_I[phase % 128];
    uint8_t q_val = VM_Q[phase % 128];

-    uint32_t mem_addr_i = REG_CH1_TX_PHS_I + (channel & 0x03) * 2;
-    uint32_t mem_addr_q = REG_CH1_TX_PHS_Q + (channel & 0x03) * 2;
+    uint32_t mem_addr_i = REG_CH1_TX_PHS_I + ((channel - 1) & 0x03) * 2;
+    uint32_t mem_addr_q = REG_CH1_TX_PHS_Q + ((channel - 1) & 0x03) * 2;

    adarWrite(deviceIndex, mem_addr_i, i_val, broadcast);
    adarWrite(deviceIndex, mem_addr_q, q_val, broadcast);
@@ -839,13 +908,23 @@ void ADAR1000Manager::adarSetTxPhase(uint8_t deviceIndex, uint8_t channel, uint8
 }

 void ADAR1000Manager::adarSetRxVgaGain(uint8_t deviceIndex, uint8_t channel, uint8_t gain, uint8_t broadcast) {
-    uint32_t mem_addr = REG_CH1_RX_GAIN + (channel & 0x03);
+    // channel is 1-based (CH1..CH4). See issue #90.
+    if (channel < 1 || channel > 4) {
+        DIAG("BF", "adarSetRxVgaGain: channel %u out of range [1..4], ignored", channel);
+        return;
+    }
+    uint32_t mem_addr = REG_CH1_RX_GAIN + ((channel - 1) & 0x03);
    adarWrite(deviceIndex, mem_addr, gain, broadcast);
    adarWrite(deviceIndex, REG_LOAD_WORKING, 0x1, broadcast);
 }

 void ADAR1000Manager::adarSetTxVgaGain(uint8_t deviceIndex, uint8_t channel, uint8_t gain, uint8_t broadcast) {
-    uint32_t mem_addr = REG_CH1_TX_GAIN + (channel & 0x03);
+    // channel is 1-based (CH1..CH4). See issue #90.
+    if (channel < 1 || channel > 4) {
+        DIAG("BF", "adarSetTxVgaGain: channel %u out of range [1..4], ignored", channel);
+        return;
+    }
+    uint32_t mem_addr = REG_CH1_TX_GAIN + ((channel - 1) & 0x03);
    adarWrite(deviceIndex, mem_addr, gain, broadcast);
    adarWrite(deviceIndex, REG_LOAD_WORKING, LD_WRK_REGS_LDTX_OVERRIDE, broadcast);
 }
@@ -116,10 +116,12 @@ public:
    bool beam_sweeping_active_ = false;
    uint32_t last_beam_update_time_ = 0;

-    // Lookup tables
+    // Vector Modulator lookup tables (see ADAR1000_Manager.cpp for provenance).
+    // Indexed as VM_*[phase % 128] on a uniform 2.8125 deg grid.
+    // No VM_GAIN[] table exists: VM magnitude is bits [4:0] of the I/Q bytes
+    // themselves; per-channel VGA gain uses a separate register.
    static const uint8_t VM_I[128];
    static const uint8_t VM_Q[128];
-    static const uint8_t VM_GAIN[128];

    // Named defaults for the ADTR1107 and ADAR1000 power sequence.
    static constexpr uint8_t kDefaultTxVgaGain = 0x7F;
@@ -1,693 +0,0 @@
-/**
- * MIT License
- * 
- * Copyright (c) 2020 Jimmy Pentz
- *
- * Reach me at: github.com/jgpentz, jpentz1(at)gmail.com
- * 
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sells
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- * 
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- * 
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-/* ADAR1000 4-Channel, X Band and Ku Band Beamformer */
-// ----------------------------------------------------------------------------
-// Includes
-// ----------------------------------------------------------------------------
-#include "main.h"
-#include "stm32f7xx_hal.h"
-#include "stm32f7xx_hal_spi.h"
-#include "stm32f7xx_hal_gpio.h"
-#include "adar1000.h"
-
-
-// ----------------------------------------------------------------------------
-// Preprocessor Definitions and Constants
-// ----------------------------------------------------------------------------
-// VM_GAIN is 15 dB of gain in 128 steps. ~0.12 dB per step.
-// A 15 dB attenuator can be applied on top of these values.
-const uint8_t VM_GAIN[128] = {
-	0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
-	0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f,
-	0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f,
-	0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f,
-	0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f,
-	0x50, 0x51, 0x52, 0x53, 0x54, 0x55, 0x56, 0x57, 0x58, 0x59, 0x5a, 0x5b, 0x5c, 0x5d, 0x5e, 0x5f,
-	0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f,
-	0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f,
-};
-
-// VM_I and VM_Q are the settings for the vector modulator. 128 steps in 360 degrees. ~2.813 degrees per step.
-const uint8_t VM_I[128] = {
-	0x3F, 0x3F, 0x3F, 0x3F, 0x3F, 0x3E, 0x3E, 0x3D, 0x3D, 0x3C, 0x3C, 0x3B, 0x3A, 0x39, 0x38, 0x37,
-	0x36, 0x35, 0x34, 0x33, 0x32, 0x30, 0x2F, 0x2E, 0x2C, 0x2B, 0x2A, 0x28, 0x27, 0x25, 0x24, 0x22,
-	0x21, 0x01, 0x03, 0x04, 0x06, 0x07, 0x08, 0x0A, 0x0B, 0x0D, 0x0E, 0x0F, 0x11, 0x12, 0x13, 0x14,
-	0x16, 0x17, 0x18, 0x19, 0x19, 0x1A, 0x1B, 0x1C, 0x1C, 0x1D, 0x1E, 0x1E, 0x1E, 0x1F, 0x1F, 0x1F,
-	0x1F, 0x1F, 0x1F, 0x1F, 0x1F, 0x1E, 0x1E, 0x1D, 0x1D, 0x1C, 0x1C, 0x1B, 0x1A, 0x19, 0x18, 0x17,
-	0x16, 0x15, 0x14, 0x13, 0x12, 0x10, 0x0F, 0x0E, 0x0C, 0x0B, 0x0A, 0x08, 0x07, 0x05, 0x04, 0x02,
-	0x01, 0x21, 0x23, 0x24, 0x26, 0x27, 0x28, 0x2A, 0x2B, 0x2D, 0x2E, 0x2F, 0x31, 0x32, 0x33, 0x34,
-	0x36, 0x37, 0x38, 0x39, 0x39, 0x3A, 0x3B, 0x3C, 0x3C, 0x3D, 0x3E, 0x3E, 0x3E, 0x3F, 0x3F, 0x3F,
-};
-
-const uint8_t VM_Q[128] = {
-	0x20, 0x21, 0x23, 0x24, 0x26, 0x27, 0x28, 0x2A, 0x2B, 0x2D, 0x2E, 0x2F, 0x30, 0x31, 0x33, 0x34,
-	0x35, 0x36, 0x37, 0x38, 0x38, 0x39, 0x3A, 0x3A, 0x3B, 0x3C, 0x3C, 0x3C, 0x3D, 0x3D, 0x3D, 0x3D,
-	0x3D, 0x3D, 0x3D, 0x3D, 0x3D, 0x3C, 0x3C, 0x3C, 0x3B, 0x3A, 0x3A, 0x39, 0x38, 0x38, 0x37, 0x36,
-	0x35, 0x34, 0x33, 0x31, 0x30, 0x2F, 0x2E, 0x2D, 0x2B, 0x2A, 0x28, 0x27, 0x26, 0x24, 0x23, 0x21,
-	0x20, 0x01, 0x03, 0x04, 0x06, 0x07, 0x08, 0x0A, 0x0B, 0x0D, 0x0E, 0x0F, 0x10, 0x11, 0x13, 0x14,
-	0x15, 0x16, 0x17, 0x18, 0x18, 0x19, 0x1A, 0x1A, 0x1B, 0x1C, 0x1C, 0x1C, 0x1D, 0x1D, 0x1D, 0x1D,
-	0x1D, 0x1D, 0x1D, 0x1D, 0x1D, 0x1C, 0x1C, 0x1C, 0x1B, 0x1A, 0x1A, 0x19, 0x18, 0x18, 0x17, 0x16,
-	0x15, 0x14, 0x13, 0x11, 0x10, 0x0F, 0x0E, 0x0D, 0x0B, 0x0A, 0x08, 0x07, 0x06, 0x04, 0x03, 0x01,
-};
-
-
-// ----------------------------------------------------------------------------
-// Function Definitions
-// ----------------------------------------------------------------------------
-/**
- * @brief	Initialize the ADC on the ADAR by setting the ADC with a 2 MHz clk, 
- *			and then enable it.
- *
- * @param	p_adar[in]	Adar pointer Which specifies the device and what function 
- *						to use for SPI transfer.
- * @param 	broadcast	Send the message as a broadcast to all ADARs in the SPI chain
- *						if this set to BROADCAST_ON.
- *
- * @warning	This is setup to only read temperature sensor data, not the power detectors.
- */
-void Adar_AdcInit(const AdarDevice * p_adar, uint8_t broadcast)
-{
-	uint8_t data;
-
-	data = ADAR1000_ADC_2MHZ_CLK | ADAR1000_ADC_EN;
-
-	Adar_Write(p_adar, REG_ADC_CONTROL, data, broadcast);
-}
-
-
-/**
- * @brief	Read a byte of data from the ADAR.
- *
- * @param	p_adar[in]	Adar pointer Which specifies the device and what function 
- *						to use for SPI transfer.
- * @param 	broadcast	Send the message as a broadcast to all ADARs in the SPI chain
- *						if this set to BROADCAST_ON.
- *
- * @return	Returns a byte of data that has been converted from the temperature sensor.
- *
- * @warning	This is setup to only read temperature sensor data, not the power detectors.
- */
-uint8_t Adar_AdcRead(const AdarDevice * p_adar, uint8_t broadcast)
-{
-	uint8_t data;
-
-    // Start the ADC conversion
-	Adar_Write(p_adar, REG_ADC_CONTROL, ADAR1000_ADC_ST_CONV, broadcast);
-
-    // This is blocking for now... wait until data is converted, then read it
-	while (!(Adar_Read(p_adar, REG_ADC_CONTROL) & 0x01))
-	{
-	}
-
-	data = Adar_Read(p_adar, REG_ADC_OUT);
-
-	return(data);
-}
-
-
-/**
- * @brief	Requests the device info from a specific ADAR and stores it in the
- *			provided AdarDeviceInfo struct.
- *
- * @param	p_adar[in]	Adar pointer Which specifies the device and what function 
- *						to use for SPI transfer.
- * @param   info[out]	Struct that contains the device info fields.
- *
- * @return	Returns ADAR_ERROR_NOERROR if information was successfully received and stored in the struct.
- */
-uint8_t Adar_GetDeviceInfo(const AdarDevice * p_adar, AdarDeviceInfo * info)
-{
-	*((uint8_t *)info) = Adar_Read(p_adar, 0x002);
-	info->chip_type = Adar_Read(p_adar, 0x003);
-	info->product_id = ((uint16_t)Adar_Read(p_adar, 0x004)) << 8;
-	info->product_id |= ((uint16_t)Adar_Read(p_adar, 0x005)) & 0x00ff;
-	info->scratchpad = Adar_Read(p_adar, 0x00A);
-	info->spi_rev = Adar_Read(p_adar, 0x00B);
-	info->vendor_id = ((uint16_t)Adar_Read(p_adar, 0x00C)) << 8;
-	info->vendor_id |= ((uint16_t)Adar_Read(p_adar, 0x00D)) & 0x00ff;
-	info->rev_id = Adar_Read(p_adar, 0x045);
-
-	return(ADAR_ERROR_NOERROR);
-}
-
-
-/**
- * @brief	Read the data that is stored in a single ADAR register.
- *
- * @param	p_adar[in]	Adar pointer Which specifies the device and what function 
- *						to use for SPI transfer.
- * @param	mem_addr	Memory address of the register you wish to read from.
- *
- * @return	Returns the byte of data that is stored in the desired register.
- *
- * @warning	This function will clear ADDR_ASCN bits.
- * @warning The ADAR does not allow for block reads.
- */
-uint8_t Adar_Read(const AdarDevice * p_adar, uint32_t mem_addr)
-{
-	uint8_t instruction[3];
-
-    // Set SDO active
-	Adar_Write(p_adar, REG_INTERFACE_CONFIG_A, INTERFACE_CONFIG_A_SDO_ACTIVE, 0);
-
-	instruction[0] = 0x80 | ((p_adar->dev_addr & 0x03) << 5);
-	instruction[0] |= ((0xff00 & mem_addr) >> 8);
-	instruction[1] = (0xff & mem_addr);
-	instruction[2] = 0x00;
-
-	p_adar->Transfer(instruction, p_adar->p_rx_buffer, ADAR1000_RD_SIZE);
-
-    // Set SDO Inactive
-	Adar_Write(p_adar, REG_INTERFACE_CONFIG_A, 0, 0);
-
-	return(p_adar->p_rx_buffer[2]);
-}
-
-
-/**
- * @brief	Block memory write to an ADAR device.
- *
- * @pre		ADDR_ASCN bits in register zero must be set!
- *
- * @param	p_adar[in]	Adar pointer Which specifies the device and what function 
- *						to use for SPI transfer.
- * @param	mem_addr  	Memory address of the register you wish to read from.
- * @param	p_data    	Pointer to block of data to transfer (must have two unused bytes preceding the data for instruction).
- * @param	size      	Size of data in bytes, including the two additional leading bytes.
- *
- * @warning First two bytes of data will be corrupted if you do not provide two unused leading bytes!
- */
-void Adar_ReadBlock(const AdarDevice * p_adar, uint16_t mem_addr, uint8_t * p_data, uint32_t size)
-{
-    // Set SDO active
-	Adar_Write(p_adar, REG_INTERFACE_CONFIG_A, INTERFACE_CONFIG_A_SDO_ACTIVE | INTERFACE_CONFIG_A_ADDR_ASCN, 0);
-
-    // Prepare command
-	p_data[0] = 0x80 | ((p_adar->dev_addr & 0x03) << 5);
-	p_data[0] |= ((mem_addr) >> 8) & 0x1F;
-	p_data[1] = (0xFF & mem_addr);
-
-    // Start the transfer
-	p_adar->Transfer(p_data, p_data, size);
-
-	Adar_Write(p_adar, REG_INTERFACE_CONFIG_A, 0, 0);
-    // Return nothing since we assume this is non-blocking and won't wait around
-}
-
-
-/**
- * @brief	Sets the Rx/Tx bias currents for the LNA, VM, and VGA to be in either
- *			low power setting or nominal setting.
- *
- * @param	p_adar[in]	Adar pointer Which specifies the device and what function 
- *						to use for SPI transfer.
- * @param	p_bias[in]	An AdarBiasCurrents struct filled with bias settings
- *						as seen in the datasheet Table 6. SPI Settings for 
- *						Different Power	Modules
- * @param 	broadcast	Send the message as a broadcast to all ADARs in the SPI chain
- *						if this set to BROADCAST_ON.
- *
- * @return	Returns ADAR_ERR_NOERROR if the bias currents were set 
- */
-uint8_t Adar_SetBiasCurrents(const AdarDevice * p_adar, AdarBiasCurrents * p_bias, uint8_t broadcast)
-{
-	uint8_t bias = 0;
-
-    // RX LNA/VGA/VM bias
-	bias = (p_bias->rx_lna & 0x0f);
-	Adar_Write(p_adar, REG_BIAS_CURRENT_RX_LNA, bias, broadcast); // RX LNA bias
-	bias = (p_bias->rx_vga & 0x07 << 3) | (p_bias->rx_vm & 0x07);
-	Adar_Write(p_adar, REG_BIAS_CURRENT_RX, bias, broadcast);     // RX VM/VGA bias
-
-    // TX VGA/VM/DRV bias
-	bias = (p_bias->tx_vga & 0x07 << 3) | (p_bias->tx_vm & 0x07);
-	Adar_Write(p_adar, REG_BIAS_CURRENT_TX, bias, broadcast);     // TX VM/VGA bias
-	bias = (p_bias->tx_drv & 0x07);
-	Adar_Write(p_adar, REG_BIAS_CURRENT_TX_DRV, bias, broadcast); // TX DRV bias
-	
-	return(ADAR_ERROR_NOERROR);
-}
-
-
-/**
- * @brief	Set the bias ON and bias OFF voltages for the four PA's and one LNA.
- *
- * @pre		This will set all 5 bias ON values and all 5 bias OFF values at once.
- * 			To enable these bias values, please see the data sheet and ensure that the BIAS_CTRL,
- * 			LNA_BIAS_OUT_EN, TR_SOURCE, TX_EN, RX_EN, TR (input to chip), and PA_ON (input to chip)
- * 			bits have all been properly set.
- *
- * @param	p_adar[in]		Adar pointer Which specifies the device and what function 
- *							to use for SPI transfer.
- * @param 	bias_on_voltage   Array that contains the bias ON voltages.
- * @param 	bias_off_voltage  Array that contains the bias OFF voltages.
- *
- * @return	Returns ADAR_ERR_NOERROR if the bias currents were set 
- */
-uint8_t Adar_SetBiasVoltages(const AdarDevice * p_adar, uint8_t bias_on_voltage[5], uint8_t bias_off_voltage[5])
-{
-	Adar_SetBit(p_adar, 0x30, 6, BROADCAST_OFF);
-	Adar_SetBit(p_adar, 0x31, 2, BROADCAST_OFF);
-	Adar_SetBit(p_adar, 0x38, 5, BROADCAST_OFF);
-	Adar_Write(p_adar, REG_PA_CH1_BIAS_ON,bias_on_voltage[0], BROADCAST_OFF);
-	Adar_Write(p_adar, REG_PA_CH2_BIAS_ON,bias_on_voltage[1], BROADCAST_OFF);
-	Adar_Write(p_adar, REG_PA_CH3_BIAS_ON,bias_on_voltage[2], BROADCAST_OFF);
-	Adar_Write(p_adar, REG_PA_CH4_BIAS_ON,bias_on_voltage[3], BROADCAST_OFF);
-
-	Adar_Write(p_adar, REG_PA_CH1_BIAS_OFF,bias_off_voltage[0], BROADCAST_OFF);
-	Adar_Write(p_adar, REG_PA_CH2_BIAS_OFF,bias_off_voltage[1], BROADCAST_OFF);
-	Adar_Write(p_adar, REG_PA_CH3_BIAS_OFF,bias_off_voltage[2], BROADCAST_OFF);
-	Adar_Write(p_adar, REG_PA_CH4_BIAS_OFF,bias_off_voltage[3], BROADCAST_OFF);
-
-	Adar_SetBit(p_adar, 0x30, 4, BROADCAST_OFF);
-	Adar_SetBit(p_adar, 0x30, 6, BROADCAST_OFF);
-	Adar_SetBit(p_adar, 0x31, 2, BROADCAST_OFF);
-	Adar_SetBit(p_adar, 0x38, 5, BROADCAST_OFF);
-	Adar_Write(p_adar, REG_LNA_BIAS_ON,bias_on_voltage[4], BROADCAST_OFF);
-	Adar_Write(p_adar, REG_LNA_BIAS_OFF,bias_off_voltage[4], BROADCAST_OFF);
-
-	Adar_ResetBit(p_adar, 0x30, 7, BROADCAST_OFF);
-	Adar_SetBit(p_adar, 0x31, 2, BROADCAST_OFF);
-	Adar_SetBit(p_adar, 0x31, 4, BROADCAST_OFF);
-	Adar_SetBit(p_adar, 0x31, 7, BROADCAST_OFF);
-	
-	return(ADAR_ERROR_NOERROR);
-}
-
-
-/**
- * @brief	Setup the ADAR to use settings that are transferred over SPI.
- *
- * @param	p_adar[in]	Adar pointer Which specifies the device and what function 
- *						to use for SPI transfer.
- * @param 	broadcast	Send the message as a broadcast to all ADARs in the SPI chain
- *						if this set to BROADCAST_ON.
- *
- * @return	Returns ADAR_ERR_NOERROR if the bias currents were set 
- */
-uint8_t Adar_SetRamBypass(const AdarDevice * p_adar, uint8_t broadcast)
-{
-	uint8_t data;
-
-	data = (MEM_CTRL_BIAS_RAM_BYPASS | MEM_CTRL_BEAM_RAM_BYPASS);
-
-	Adar_Write(p_adar, REG_MEM_CTL, data, broadcast);
-
-	return(ADAR_ERROR_NOERROR);
-}
-
-
-/**
- * @brief	Set the VGA gain value of a Receive channel in dB.
- *
- * @param	p_adar[in]		Adar pointer Which specifies the device and what function 
- *							to use for SPI transfer.
- * @param 	channel			Channel in which to set the gain (1-4).
- * @param 	vga_gain_db		Gain to be applied to the channel, ranging from 0 - 30 dB. 
- *							(Intended operation >16 dB).
- * @param 	broadcast	Send the message as a broadcast to all ADARs in the SPI chain
- *						if this set to BROADCAST_ON.
- *
- * @return 	Returns ADAR_ERROR_NOERROR if the gain was successfully set. 
- * 					ADAR_ERROR_FAILED if an invalid channel was selected.
- *
- * @warning 0 dB or 15 dB step attenuator may also be turned on, which is why intended operation is >16 dB.
- */
-uint8_t Adar_SetRxVgaGain(const AdarDevice * p_adar, uint8_t channel, uint8_t vga_gain_db, uint8_t broadcast)
-{
-	uint8_t	 vga_gain_bits = (uint8_t)(255*vga_gain_db/16);
-	uint32_t mem_addr = 0;
-
-	if((channel == 0) || (channel > 4))
-	{
-		return(ADAR_ERROR_FAILED);
-	}
-
-	mem_addr = REG_CH1_RX_GAIN + (channel & 0x03);
-
-    // Set gain
-	Adar_Write(p_adar, mem_addr, vga_gain_bits, broadcast);
-
-    // Load the new setting
-	Adar_Write(p_adar, REG_LOAD_WORKING, 0x1, broadcast);
-
-	return(ADAR_ERROR_NOERROR);
-}
-
-
-/**
- * @brief	Set the phase of a given receive channel using the I/Q vector modulator.
- *
- * @pre		According to the given @param phase, this sets the polarity (bit 5) and gain (bits 4-0)
- * 			of the @param channel, and then loads them into the working register.
- * 			A vector modulator I/Q look-up table has been provided at the beginning of this library.
- *
- * @param	p_adar[in]	Adar pointer Which specifies the device and what function 
- *						to use for SPI transfer.
- * @param	channel   	Channel in which to set the gain (1-4).
- * @param	phase     	Byte that is used to set the polarity (bit 5) and gain (bits 4-0).
- * @param 	broadcast	Send the message as a broadcast to all ADARs in the SPI chain
- *						if this set to BROADCAST_ON.
- *
- * @return 	Returns ADAR_ERROR_NOERROR if the phase was successfully set. 
- * 					ADAR_ERROR_FAILED if an invalid channel was selected.
- *
- * @note    To obtain your phase:
- *          phase = degrees * 128;
- *          phase /= 360;
- */
-uint8_t Adar_SetRxPhase(const AdarDevice * p_adar, uint8_t channel, uint8_t phase, uint8_t broadcast)
-{
-	uint8_t	 i_val = 0;
-	uint8_t	 q_val = 0;
-	uint32_t mem_addr_i, mem_addr_q;
-
-	if((channel == 0) || (channel > 4))
-	{
-		return(ADAR_ERROR_FAILED);
-	}
-
-	//phase = phase % 128;
-	i_val = VM_I[phase];
-	q_val = VM_Q[phase];
-
-	mem_addr_i = REG_CH1_RX_PHS_I + (channel & 0x03) * 2;
-	mem_addr_q = REG_CH1_RX_PHS_Q + (channel & 0x03) * 2;
-
-	Adar_Write(p_adar, mem_addr_i, i_val, broadcast);
-	Adar_Write(p_adar, mem_addr_q, q_val, broadcast);
-	Adar_Write(p_adar, REG_LOAD_WORKING, 0x1, broadcast);
-
-	return(ADAR_ERROR_NOERROR);
-}
-
-
-/**
- * @brief	Set the VGA gain value of a Tx channel in dB.
- *
- * @param	p_adar[in]	Adar pointer Which specifies the device and what function 
- *						to use for SPI transfer.
- * @param 	broadcast	Send the message as a broadcast to all ADARs in the SPI chain
- *						if this set to BROADCAST_ON.
- *
- * @return 	Returns ADAR_ERROR_NOERROR if the bias was successfully set. 
- * 					ADAR_ERROR_FAILED if an invalid channel was selected.
- *
- * @warning 0 dB or 15 dB step attenuator may also be turned on, which is why intended operation is >16 dB.
- */
-uint8_t Adar_SetTxBias(const AdarDevice * p_adar, uint8_t broadcast)
-{
-	uint8_t	 vga_bias_bits;
-	uint8_t	 drv_bias_bits;
-	uint32_t mem_vga_bias;
-	uint32_t mem_drv_bias;
-
-	mem_vga_bias = REG_BIAS_CURRENT_TX;
-	mem_drv_bias = REG_BIAS_CURRENT_TX_DRV;
-
-    // Set bias to nom
-	vga_bias_bits = 0x2D;
-	drv_bias_bits = 0x06;
-
-    // Set bias
-	Adar_Write(p_adar, mem_vga_bias, vga_bias_bits, broadcast);
-    // Set bias
-	Adar_Write(p_adar, mem_drv_bias, drv_bias_bits, broadcast);
-
-    // Load the new setting
-	Adar_Write(p_adar, REG_LOAD_WORKING, 0x2, broadcast);
-
-	return(ADAR_ERROR_NOERROR);
-}
-
-
-/**
- * @brief	Set the VGA gain value of a Tx channel.
- *
- * @param	p_adar[in]	Adar pointer Which specifies the device and what function 
- *						to use for SPI transfer.
- * @param 	channel     Tx channel in which to set the gain, ranging from 1 - 4.
- * @param 	gain   		Gain to be applied to the channel, ranging from 0 - 127,
- *						plus the MSb 15dB attenuator (Intended operation >16 dB).
- * @param 	broadcast	Send the message as a broadcast to all ADARs in the SPI chain
- *						if this set to BROADCAST_ON.
- *
- * @return 	Returns ADAR_ERROR_NOERROR if the gain was successfully set. 
- * 					ADAR_ERROR_FAILED if an invalid channel was selected.
- *
- * @warning 0 dB or 15 dB step attenuator may also be turned on, which is why intended operation is >16 dB.
- */
-uint8_t Adar_SetTxVgaGain(const AdarDevice * p_adar, uint8_t channel, uint8_t gain, uint8_t broadcast)
-{
-	uint32_t mem_addr;
-	
-	if((channel == 0) || (channel > 4))
-	{
-		return(ADAR_ERROR_FAILED);
-	}
-
-	mem_addr = REG_CH1_TX_GAIN + (channel & 0x03);
-
-    // Set gain
-	Adar_Write(p_adar, mem_addr, gain, broadcast);
-
-    // Load the new setting
-	Adar_Write(p_adar, REG_LOAD_WORKING, LD_WRK_REGS_LDTX_OVERRIDE, broadcast);
-
-	return(ADAR_ERROR_NOERROR);
-}
-
-
-/**
- * @brief 	Set the phase of a given transmit channel using the I/Q vector modulator.
- *
- * @pre		According to the given @param phase, this sets the polarity (bit 5) and gain (bits 4-0)
- * 			of the @param channel, and then loads them into the working register.
- * 			A vector modulator I/Q look-up table has been provided at the beginning of this library.
- *
- * @param	p_adar[in]	Adar pointer Which specifies the device and what function 
- *						to use for SPI transfer.
- * @param 	channel   	Channel in which to set the gain (1-4).
- * @param 	phase     	Byte that is used to set the polarity (bit 5) and gain (bits 4-0).
- * @param 	broadcast	Send the message as a broadcast to all ADARs in the SPI chain
- *						if this set to BROADCAST_ON.
- *
- * @return 	Returns ADAR_ERROR_NOERROR if the phase was successfully set. 
- * 					ADAR_ERROR_FAILED if an invalid channel was selected.
- *
- * @note    To obtain your phase:
- *          phase = degrees * 128;
- *          phase /= 360;
- */
-uint8_t Adar_SetTxPhase(const AdarDevice * p_adar, uint8_t channel, uint8_t phase, uint8_t broadcast)
-{
-	uint8_t	 i_val = 0;
-	uint8_t	 q_val = 0;
-	uint32_t mem_addr_i, mem_addr_q;
-
-	if((channel == 0) || (channel > 4))
-	{
-		return(ADAR_ERROR_FAILED);
-	}
-
-	//phase = phase % 128;
-	i_val = VM_I[phase];
-	q_val = VM_Q[phase];
-
-	mem_addr_i = REG_CH1_TX_PHS_I + (channel & 0x03) * 2;
-	mem_addr_q = REG_CH1_TX_PHS_Q + (channel & 0x03) * 2;
-
-	Adar_Write(p_adar, mem_addr_i, i_val, broadcast);
-	Adar_Write(p_adar, mem_addr_q, q_val, broadcast);
-	Adar_Write(p_adar, REG_LOAD_WORKING, 0x1, broadcast);
-
-	return(ADAR_ERROR_NOERROR);
-}
-
-
-/**
- * @brief 	Reset the whole ADAR device.
- *
- * @param	p_adar[in]	ADAR pointer Which specifies the device and what function 
- *						to use for SPI transfer.
- */
-void Adar_SoftReset(const AdarDevice * p_adar)
-{
-	uint8_t instruction[3];
-
-	instruction[0] = ((p_adar->dev_addr & 0x03) << 5);
-	instruction[1] = 0x00;
-	instruction[2] = 0x81;
-
-	p_adar->Transfer(instruction, NULL, sizeof(instruction));
-}
-
-
-/**
- * @brief 	Reset ALL ADAR devices in the SPI chain.
- *
- * @param	p_adar[in]	Adar pointer Which specifies the device and what function 
- *						to use for SPI transfer.
- */
-void Adar_SoftResetAll(const AdarDevice * p_adar)
-{
-	uint8_t instruction[3];
-
-	instruction[0] = 0x08;
-	instruction[1] = 0x00;
-	instruction[2] = 0x81;
-
-	p_adar->Transfer(instruction, NULL, sizeof(instruction));
-}
-
-
-/**
- * @brief 	Write a byte of @param data to the register located at @param mem_addr.
- *
- * @param	p_adar[in]	Adar pointer Which specifies the device and what function 
- *						to use for SPI transfer.
- * @param 	mem_addr  	Memory address of the register you wish to read from.
- * @param 	data      	Byte of data to be stored in the register.
- * @param 	broadcast	Send the message as a broadcast to all ADARs in the SPI chain
- 						if this set to BROADCAST_ON.
- *
- * @warning If writing the same data to multiple registers, use ADAR_WriteBlock.
- */
-void Adar_Write(const AdarDevice * p_adar, uint32_t mem_addr, uint8_t data, uint8_t broadcast)
-{
-	uint8_t instruction[3];
-	
-	if (broadcast)
-	{
-		instruction[0] = 0x08;
-	}
-	else
-	{
-		instruction[0] = ((p_adar->dev_addr & 0x03) << 5);
-	}
-
-	instruction[0] |= (0x1F00 & mem_addr) >> 8;
-	instruction[1] = (0xFF & mem_addr);
-	instruction[2] = data;
-
-	p_adar->Transfer(instruction, NULL, sizeof(instruction));
-}
-
-
-/**
- * @brief 	Block memory write to an ADAR device.
- *
- * @pre 	ADDR_ASCN BITS IN REGISTER ZERO MUST BE SET!
- *
- * @param	p_adar[in]	Adar pointer Which specifies the device and what function 
- *						to use for SPI transfer.
- * @param	mem_addr 	Memory address of the register you wish to read from.
- * @param	p_data[in]  Pointer to block of data to transfer (must have two unused bytes 
- 						preceding the data for instruction).
- * @param	size      	Size of data in bytes, including the two additional leading bytes.
- *
- * @warning First two bytes of data will be corrupted if you do not provide two unused leading bytes!
- */
-void Adar_WriteBlock(const AdarDevice * p_adar, uint16_t mem_addr, uint8_t * p_data, uint32_t size)
-{
-    // Prepare command
-	p_data[0] = ((p_adar->dev_addr & 0x03) << 5);
-	p_data[0] |= ((mem_addr) >> 8) & 0x1F;
-	p_data[1] = (0xFF & mem_addr);
-
-    // Start the transfer
-	p_adar->Transfer(p_data, NULL, size);
-
-    // Return nothing since we assume this is non-blocking and won't wait around
-}
-
-
-/**
- * @brief	Set contents of the INTERFACE_CONFIG_A register.
- *
- * @param	p_adar[in]	Adar pointer Which specifies the device and what function 
- *						to use for SPI transfer.
- * @param 	flags     	#INTERFACE_CONFIG_A_SOFTRESET, #INTERFACE_CONFIG_A_LSB_FIRST,
- *                  	#INTERFACE_CONFIG_A_ADDR_ASCN, #INTERFACE_CONFIG_A_SDO_ACTIVE
- * @param 	broadcast	Send the message as a broadcast to all ADARs in the SPI chain
- *						if this set to BROADCAST_ON.
- */
-void Adar_WriteConfigA(const AdarDevice * p_adar, uint8_t flags, uint8_t broadcast)
-{
-	Adar_Write(p_adar, 0x00, flags, broadcast);
-}
-
-
-/**
- * @brief 	Write a byte of @param data to the register located at @param mem_addr and
- *			then read from the device and verify that the register was correctly set.
- *
- * @param	p_adar[in]	Adar pointer Which specifies the device and what function 
- *						to use for SPI transfer.
- * @param 	mem_addr  	Memory address of the register you wish to read from.
- * @param 	data      	Byte of data to be stored in the register.
- *
- * @return	Returns the number of attempts that it took to successfully write to a register,
- *			starting from zero.
- * @warning This function currently only supports writes to a single regiter in a single ADAR.
- */
-uint8_t Adar_WriteVerify(const AdarDevice * p_adar, uint32_t mem_addr, uint8_t data)
-{
-	uint8_t rx_data;
-
-	for (uint8_t ii = 0; ii < 3; ii++)
-	{
-		Adar_Write(p_adar, mem_addr, data, 0);
-
-		// Can't read back from an ADAR with HW address 0
-		if (!((p_adar->dev_addr) % 4))
-		{
-			return(ADAR_ERROR_INVALIDADDR);
-		}
-		rx_data = Adar_Read(p_adar, mem_addr);
-		if (rx_data == data)
-		{
-			return(ii);
-		}
-	}
-
-	return(ADAR_ERROR_FAILED);
-}
-
-void Adar_SetBit(const AdarDevice * p_adar, uint32_t mem_addr, uint8_t bit, uint8_t broadcast)
-	{
-		uint8_t temp = Adar_Read(p_adar, mem_addr);
-		uint8_t data = temp|(1<<bit);
-		Adar_Write(p_adar,mem_addr, data,broadcast);
-	}
-
-void Adar_ResetBit(const AdarDevice * p_adar, uint32_t mem_addr, uint8_t bit, uint8_t broadcast)
-	{
-		uint8_t temp = Adar_Read(p_adar, mem_addr);
-		uint8_t data = temp&~(1<<bit);
-		Adar_Write(p_adar,mem_addr, data,broadcast);
-	}
-
@@ -1,294 +0,0 @@
-/**
- * MIT License
- * 
- * Copyright (c) 2020 Jimmy Pentz
- *
- * Reach me at: github.com/jgpentz, jpentz1( at )gmail.com
- * 
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sells
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- * 
- * The above copyright notice and this permission notice shall be included in all
- * copies or substantial portions of the Software.
- * 
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
- * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
- * SOFTWARE.
- */
-/* ADAR1000 4-Channel, X Band and Ku Band Beamformer */
-#ifndef LIB_ADAR1000_H_
-#define LIB_ADAR1000_H_
-
-#ifndef NULL
-#define NULL    (0)
-#endif
-
-// ----------------------------------------------------------------------------
-// Includes
-// ----------------------------------------------------------------------------
-#include "main.h"
-#include "stm32f7xx_hal.h"
-#include "stm32f7xx_hal_spi.h"
-#include "stm32f7xx_hal_gpio.h"
-#include <stdbool.h>
-#include <stdint.h>
-#include <string.h>
-
-#ifdef __cplusplus
-extern "C" {  // Prevent C++ name mangling
-#endif
-
-
-
-
-// ----------------------------------------------------------------------------
-// Datatypes
-// ----------------------------------------------------------------------------
-extern SPI_HandleTypeDef hspi1;
-extern const uint8_t VM_GAIN[128];
-extern const uint8_t VM_I[128];
-extern const uint8_t VM_Q[128];
-
-/// A function pointer prototype for a SPI transfer, the 3 parameters would be
-/// p_txData, p_rxData, and size (number of bytes to transfer), respectively.
-typedef uint32_t (*Adar_SpiTransfer)( uint8_t *, uint8_t *, uint32_t);
-
-typedef struct
- {
- 	uint8_t			 dev_addr; 		///< 2-bit device hardware address, 0x00, 0x01, 0x10, 0x11
- 	Adar_SpiTransfer Transfer;		///< Function pointer to the function used for SPI transfers
- 	uint8_t *		 p_rx_buffer;	///< Data buffer to store received bytes into
- }const AdarDevice;
-
-
-/// Use this to store bias current values into, as seen in the datasheet 
-/// Table 6. SPI Settings for Different Power Modules
-typedef struct
-{
-	uint8_t rx_lna;		///< nominal:  8, low power: 5
-	uint8_t rx_vm;		///< nominal:  5, low power: 2
-	uint8_t rx_vga;		///< nominal: 10, low power: 3
-	uint8_t tx_vm;		///< nominal:  5, low power: 2
-	uint8_t tx_vga;		///< nominal:  5, low power: 5
-	uint8_t tx_drv;		///< nominal:  6, low power: 3
-} AdarBiasCurrents;
-
-/// Useful for queries regarding the device info
-typedef struct
-{
-	uint8_t	 norm_operating_mode : 2;
-	uint8_t	 cust_operating_mode : 2;
-	uint8_t	 dev_status : 4;
-	uint8_t	 chip_type;
-	uint16_t product_id;
-	uint8_t	 scratchpad;
-	uint8_t	 spi_rev;
-	uint16_t vendor_id;
-	uint8_t	 rev_id;
-} AdarDeviceInfo;
-
-/// Return types for functions in this library
-typedef enum {
-	ADAR_ERROR_NOERROR		= 0,
-	ADAR_ERROR_FAILED		= 1,
-	ADAR_ERROR_INVALIDADDR	= 2,
-} AdarErrorCodes;
-
-
-// ----------------------------------------------------------------------------
-// Function Prototypes
-// ----------------------------------------------------------------------------
-void Adar_AdcInit(const AdarDevice * p_adar, uint8_t broadcast_bit);
-
-uint8_t Adar_AdcRead(const AdarDevice * p_adar, uint8_t broadcast_bit);
-
-uint8_t Adar_GetDeviceInfo(const AdarDevice * p_adar, AdarDeviceInfo * info);
-
-uint8_t Adar_Read(const AdarDevice * p_adar, uint32_t mem_addr);
-
-void Adar_ReadBlock(const AdarDevice * p_adar, uint16_t mem_addr, uint8_t * p_data, uint32_t size);
-
-uint8_t Adar_SetBiasCurrents(const AdarDevice * p_adar, AdarBiasCurrents * p_bias, uint8_t broadcast_bit);
-
-uint8_t Adar_SetBiasVoltages(const AdarDevice * p_adar, uint8_t bias_on_voltage[5], uint8_t bias_off_voltage[5]);
-
-uint8_t Adar_SetRamBypass(const AdarDevice * p_adar, uint8_t broadcast_bit);
-
-uint8_t Adar_SetRxVgaGain(const AdarDevice * p_adar, uint8_t channel, uint8_t vga_gain_db, uint8_t broadcast_bit);
-
-uint8_t Adar_SetRxPhase(const AdarDevice * p_adar, uint8_t channel, uint8_t phase, uint8_t broadcast_bit);
-
-uint8_t Adar_SetTxBias(const AdarDevice * p_adar, uint8_t broadcast_bit);
-
-uint8_t Adar_SetTxVgaGain(const AdarDevice * p_adar, uint8_t channel, uint8_t vga_gain_db, uint8_t broadcast_bit);
-
-uint8_t Adar_SetTxPhase(const AdarDevice * p_adar, uint8_t channel, uint8_t phase, uint8_t broadcast_bit);
-
-void Adar_SoftReset(const AdarDevice * p_adar);
-
-void Adar_SoftResetAll(const AdarDevice * p_adar);
-
-void Adar_Write(const AdarDevice * p_adar, uint32_t mem_addr, uint8_t data, uint8_t broadcast_bit);
-
-void Adar_WriteBlock(const AdarDevice * p_adar, uint16_t mem_addr, uint8_t * p_data, uint32_t size);
-
-void Adar_WriteConfigA(const AdarDevice * p_adar, uint8_t flags, uint8_t broadcast);
-
-uint8_t Adar_WriteVerify(const AdarDevice * p_adar, uint32_t mem_addr, uint8_t data);
-
-void Adar_SetBit(const AdarDevice * p_adar, uint32_t mem_addr, uint8_t bit, uint8_t broadcast);
-
-void Adar_ResetBit(const AdarDevice * p_adar, uint32_t mem_addr, uint8_t bit, uint8_t broadcast);
-
-
-// ----------------------------------------------------------------------------
-// Preprocessor Definitions and Constants
-// ----------------------------------------------------------------------------
-// Using BROADCAST_ON will send a command to all ADARs that share a bus
-#define BROADCAST_OFF					 0
-#define BROADCAST_ON					 1
-
-// The minimum size of a read from the ADARs consists of 3 bytes
-#define ADAR1000_RD_SIZE				 3
-
-// Address at which the TX RAM starts
-#define ADAR_TX_RAM_START_ADDR			 0x1800
-
-// ADC Defines
-#define ADAR1000_ADC_2MHZ_CLK			 0x00
-#define ADAR1000_ADC_EN					 0x60
-#define ADAR1000_ADC_ST_CONV			 0x70
-
-/* REGISTER DEFINITIONS */
-#define REG_INTERFACE_CONFIG_A			 0x000
-#define REG_INTERFACE_CONFIG_B			 0x001
-#define REG_DEV_CONFIG					 0x002
-#define REG_SCRATCHPAD					 0x00A
-#define REG_TRANSFER					 0x00F
-#define REG_CH1_RX_GAIN					 0x010
-#define REG_CH2_RX_GAIN					 0x011
-#define REG_CH3_RX_GAIN					 0x012
-#define REG_CH4_RX_GAIN					 0x013
-#define REG_CH1_RX_PHS_I				 0x014
-#define REG_CH1_RX_PHS_Q				 0x015
-#define REG_CH2_RX_PHS_I				 0x016
-#define REG_CH2_RX_PHS_Q				 0x017
-#define REG_CH3_RX_PHS_I				 0x018
-#define REG_CH3_RX_PHS_Q				 0x019
-#define REG_CH4_RX_PHS_I				 0x01A
-#define REG_CH4_RX_PHS_Q				 0x01B
-#define REG_CH1_TX_GAIN					 0x01C
-#define REG_CH2_TX_GAIN					 0x01D
-#define REG_CH3_TX_GAIN					 0x01E
-#define REG_CH4_TX_GAIN					 0x01F
-#define REG_CH1_TX_PHS_I				 0x020
-#define REG_CH1_TX_PHS_Q				 0x021
-#define REG_CH2_TX_PHS_I				 0x022
-#define REG_CH2_TX_PHS_Q				 0x023
-#define REG_CH3_TX_PHS_I				 0x024
-#define REG_CH3_TX_PHS_Q				 0x025
-#define REG_CH4_TX_PHS_I				 0x026
-#define REG_CH4_TX_PHS_Q				 0x027
-#define REG_LOAD_WORKING				 0x028
-#define REG_PA_CH1_BIAS_ON				 0x029
-#define REG_PA_CH2_BIAS_ON				 0x02A
-#define REG_PA_CH3_BIAS_ON				 0x02B
-#define REG_PA_CH4_BIAS_ON				 0x02C
-#define REG_LNA_BIAS_ON					 0x02D
-#define REG_RX_ENABLES					 0x02E
-#define REG_TX_ENABLES					 0x02F
-#define REG_MISC_ENABLES				 0x030
-#define REG_SW_CONTROL					 0x031
-#define REG_ADC_CONTROL					 0x032
-#define REG_ADC_CONTROL_TEMP_EN			 0xf0
-#define REG_ADC_OUT						 0x033
-#define REG_BIAS_CURRENT_RX_LNA			 0x034
-#define REG_BIAS_CURRENT_RX				 0x035
-#define REG_BIAS_CURRENT_TX				 0x036
-#define REG_BIAS_CURRENT_TX_DRV			 0x037
-#define REG_MEM_CTL						 0x038
-#define REG_RX_CHX_MEM					 0x039
-#define REG_TX_CHX_MEM					 0x03A
-#define REG_RX_CH1_MEM					 0x03D
-#define REG_RX_CH2_MEM					 0x03E
-#define REG_RX_CH3_MEM					 0x03F
-#define REG_RX_CH4_MEM					 0x040
-#define REG_TX_CH1_MEM					 0x041
-#define REG_TX_CH2_MEM					 0x042
-#define REG_TX_CH3_MEM					 0x043
-#define REG_TX_CH4_MEM					 0x044
-#define REG_PA_CH1_BIAS_OFF				 0x046
-#define REG_PA_CH2_BIAS_OFF				 0x047
-#define REG_PA_CH3_BIAS_OFF				 0x048
-#define REG_PA_CH4_BIAS_OFF				 0x049
-#define REG_LNA_BIAS_OFF				 0x04A
-#define REG_TX_BEAM_STEP_START			 0x04D
-#define REG_TX_BEAM_STEP_STOP			 0x04E
-#define REG_RX_BEAM_STEP_START			 0x04F
-#define REG_RX_BEAM_STEP_STOP			 0x050
-
-// REGISTER CONSTANTS
-#define INTERFACE_CONFIG_A_SOFTRESET	 	((1 << 7) | (1 << 0))
-#define INTERFACE_CONFIG_A_LSB_FIRST	 	((1 << 6) | (1 << 1))
-#define INTERFACE_CONFIG_A_ADDR_ASCN	 	((1 << 5) | (1 << 2))
-#define INTERFACE_CONFIG_A_SDO_ACTIVE		((1 << 4) | (1 << 3))
-
-#define LD_WRK_REGS_LDRX_OVERRIDE		   	(1 << 0)
-#define LD_WRK_REGS_LDTX_OVERRIDE		   	(1 << 1)
-
-#define RX_ENABLES_TX_VGA_EN			   	(1 << 0)
-#define RX_ENABLES_TX_VM_EN				   	(1 << 1)
-#define RX_ENABLES_TX_DRV_EN			   	(1 << 2)
-#define RX_ENABLES_CH3_TX_EN			   	(1 << 3)
-#define RX_ENABLES_CH2_TX_EN			   	(1 << 4)
-#define RX_ENABLES_CH1_TX_EN			   	(1 << 5)
-#define RX_ENABLES_CH0_TX_EN			   	(1 << 6)
-
-#define TX_ENABLES_TX_VGA_EN			   	(1 << 0)
-#define TX_ENABLES_TX_VM_EN				   	(1 << 1)
-#define TX_ENABLES_TX_DRV_EN			   	(1 << 2)
-#define TX_ENABLES_CH3_TX_EN			   	(1 << 3)
-#define TX_ENABLES_CH2_TX_EN			   	(1 << 4)
-#define TX_ENABLES_CH1_TX_EN			   	(1 << 5)
-#define TX_ENABLES_CH0_TX_EN			   	(1 << 6)
-
-#define MISC_ENABLES_CH4_DET_EN			   	(1 << 0)
-#define MISC_ENABLES_CH3_DET_EN			   	(1 << 1)
-#define MISC_ENABLES_CH2_DET_EN			   	(1 << 2)
-#define MISC_ENABLES_CH1_DET_EN			   	(1 << 3)
-#define MISC_ENABLES_LNA_BIAS_OUT_EN	   	(1 << 4)
-#define MISC_ENABLES_BIAS_EN			   	(1 << 5)
-#define MISC_ENABLES_BIAS_CTRL			   	(1 << 6)
-#define MISC_ENABLES_SW_DRV_TR_MODE_SEL	   	(1 << 7)
-
-#define SW_CTRL_POL						   	(1 << 0)
-#define SW_CTRL_TR_SPI					   	(1 << 1)
-#define SW_CTRL_TR_SOURCE				   	(1 << 2)
-#define SW_CTRL_SW_DRV_EN_POL			   	(1 << 3)
-#define SW_CTRL_SW_DRV_EN_TR			   	(1 << 4)
-#define SW_CTRL_RX_EN					   	(1 << 5)
-#define SW_CTRL_TX_EN					   	(1 << 6)
-#define SW_CTRL_SW_DRV_TR_STATE			   	(1 << 7)
-
-#define MEM_CTRL_RX_CHX_RAM_BYPASS		   	(1 << 0)
-#define MEM_CTRL_TX_CHX_RAM_BYPASS		   	(1 << 1)
-#define MEM_CTRL_RX_BEAM_STEP_EN		   	(1 << 2)
-#define MEM_CTRL_TX_BEAM_STEP_EN		   	(1 << 3)
-#define MEM_CTRL_BIAS_RAM_BYPASS		   	(1 << 5)
-#define MEM_CTRL_BEAM_RAM_BYPASS		   	(1 << 6)
-#define MEM_CTRL_SCAN_MODE_EN			   	(1 << 7)
-
-#ifdef __cplusplus
-}  // End extern "C"
-#endif
-
-#endif /* LIB_ADAR1000_H_ */
-
@@ -112,7 +112,7 @@ extern "C" {
 *   "BF"    -- ADAR1000 beamformer
 *   "PA"    -- Power amplifier bias/monitoring
 *   "FPGA"  -- FPGA communication and handshake
- *   "USB"   -- FT601 USB data path
+ *   "USB"   -- USB data path (FT2232H production / FT601 premium)
 *   "PWR"   -- Power sequencing and rail monitoring
 *   "IMU"   -- IMU/GPS/barometer sensors
 *   "MOT"   -- Stepper motor/scan mechanics
@@ -21,7 +21,6 @@
 #include "usb_device.h"
 #include "USBHandler.h"
 #include "usbd_cdc_if.h"
-#include "adar1000.h"
 #include "ADAR1000_Manager.h"
 #include "ADAR1000_AGC.h"
 extern "C" {
@@ -2180,9 +2179,24 @@ int main(void)

      runRadarPulseSequence();

-      /* [AGC] Outer-loop AGC: read FPGA saturation flag (DIG_5 / PD13),
-       * adjust ADAR1000 VGA common gain once per radar frame (~258 ms).
-       * Only run when AGC is enabled — otherwise leave VGA gains untouched. */
+      /* [AGC] Outer-loop AGC: sync enable from FPGA via DIG_6 (PD14),
+       * then read saturation flag (DIG_5 / PD13) and adjust ADAR1000 VGA
+       * common gain once per radar frame (~258 ms).
+       * FPGA register host_agc_enable is the single source of truth —
+       * DIG_6 propagates it to MCU every frame.
+       * 2-frame confirmation debounce: only change outerAgc.enabled when
+       * two consecutive frames read the same DIG_6 value. Prevents a
+       * single-sample glitch from causing a spurious AGC state transition.
+       * Added latency: 1 extra frame (~258 ms), acceptable for control plane. */
+      {
+          bool dig6_now = (HAL_GPIO_ReadPin(FPGA_DIG6_GPIO_Port,
+                                            FPGA_DIG6_Pin) == GPIO_PIN_SET);
+          static bool dig6_prev = false;  // matches boot default (AGC off)
+          if (dig6_now == dig6_prev) {
+              outerAgc.enabled = dig6_now;
+          }
+          dig6_prev = dig6_now;
+      }
      if (outerAgc.enabled) {
          bool sat = HAL_GPIO_ReadPin(FPGA_DIG5_SAT_GPIO_Port,
                                      FPGA_DIG5_SAT_Pin) == GPIO_PIN_SET;
@@ -50,7 +50,7 @@ static void test_defaults()
    assert(agc.min_gain == 0);
    assert(agc.max_gain == 127);
    assert(agc.holdoff_frames == 4);
-    assert(agc.enabled == true);
+    assert(agc.enabled == false);  // disabled by default — FPGA DIG_6 is source of truth
    assert(agc.holdoff_counter == 0);
    assert(agc.last_saturated == false);
    assert(agc.saturation_event_count == 0);
@@ -67,6 +67,7 @@ static void test_defaults()
 static void test_saturation_reduces_gain()
 {
    ADAR1000_AGC agc;
+    agc.enabled = true;  // default is OFF; enable for this test
    uint8_t initial = agc.agc_base_gain;  // 30

    agc.update(true);  // saturation
@@ -82,6 +83,7 @@ static void test_saturation_reduces_gain()
 static void test_holdoff_prevents_early_gain_up()
 {
    ADAR1000_AGC agc;
+    agc.enabled = true;  // default is OFF; enable for this test
    agc.update(true);  // saturate once -> gain = 26
    uint8_t after_sat = agc.agc_base_gain;

@@ -101,6 +103,7 @@ static void test_holdoff_prevents_early_gain_up()
 static void test_recovery_after_holdoff()
 {
    ADAR1000_AGC agc;
+    agc.enabled = true;  // default is OFF; enable for this test
    agc.update(true);  // saturate -> gain = 26
    uint8_t after_sat = agc.agc_base_gain;

@@ -119,6 +122,7 @@ static void test_recovery_after_holdoff()
 static void test_min_gain_clamp()
 {
    ADAR1000_AGC agc;
+    agc.enabled = true;  // default is OFF; enable for this test
    agc.min_gain = 10;
    agc.agc_base_gain = 12;
    agc.gain_step_down = 4;
@@ -136,6 +140,7 @@ static void test_min_gain_clamp()
 static void test_max_gain_clamp()
 {
    ADAR1000_AGC agc;
+    agc.enabled = true;  // default is OFF; enable for this test
    agc.max_gain = 32;
    agc.agc_base_gain = 31;
    agc.gain_step_up = 2;
@@ -226,6 +231,7 @@ static void test_apply_gain_spi()
 static void test_reset_preserves_config()
 {
    ADAR1000_AGC agc;
+    agc.enabled = true;  // default is OFF; enable for this test
    agc.agc_base_gain = 42;
    agc.gain_step_down = 8;
    agc.cal_offset[3] = -5;
@@ -255,6 +261,7 @@ static void test_reset_preserves_config()
 static void test_saturation_counter()
 {
    ADAR1000_AGC agc;
+    agc.enabled = true;  // default is OFF; enable for this test

    for (int i = 0; i < 10; ++i) {
        agc.update(true);
@@ -274,6 +281,7 @@ static void test_saturation_counter()
 static void test_mixed_sequence()
 {
    ADAR1000_AGC agc;
+    agc.enabled = true;  // default is OFF; enable for this test
    agc.agc_base_gain = 30;
    agc.gain_step_down = 4;
    agc.gain_step_up = 1;
@@ -32,11 +32,50 @@ localparam COMB_WIDTH = 28;
 // adjacent DSP48E1 tiles — zero fabric delay, guaranteed to meet 400+ MHz
 // on 7-series regardless of speed grade.
 //
-// Active-high reset derived from reset_n (inverted).
+// Active-high reset derived from reset_n (inverted and REGISTERED).
 // CEP (clock enable for P register) gated by data_valid.
-// ============================================================================
-
-wire reset_h = ~reset_n;  // active-high reset for DSP48E1 RSTP
+//
+// ----------------------------------------------------------------------------
+// RESET FAN-OUT INVARIANT (Build N+1 fix for WNS=-0.626ns at 400 MHz):
+// ----------------------------------------------------------------------------
+// Previously this was a combinational wire (`wire reset_h = ~reset_n`). Vivado
+// collapsed all per-module inversions across the DDC hierarchy into a SINGLE
+// shared LUT1, whose output fanned out to 702 loads (DSP48E1 RSTP/RSTB/RSTC
+// plus FDRE R pins of all comb-stage DSP48E1s inferred via use_dsp="yes").
+// Route delay alone on that net was 2.019–2.268 ns — nearly one full 2.5 ns
+// period. Timing failed by 626 ps on the 400 MHz domain.
+//
+// Fix: convert reset_h to a REGISTERED signal with (* max_fanout = 50 *).
+// Vivado treats max_fanout on a REG (not a wire) as authoritative and
+// replicates the register into N copies, each placed near its ≈50 loads.
+// Invariants preserved:
+//   I1 (correctness):       reset_h is still active-high, equals ~reset_n
+//                           after one clk edge; CIC reset is a RECEIVER-side
+//                           synchronizer anyway (driven by reset_n_400m which
+//                           is already sync'd in the parent DDC), so adding
+//                           one more clk cycle of latency is safe.
+//   I2 (glitch-free):       Registered output => inherently glitch-free,
+//                           feeding DSP48E1 RST pins (which are synchronous
+//                           to CLK, so they capture on the same edge anyway).
+//   I3 (power-up safety):   reset_h is NOT async-reset itself. On power-up,
+//                           FDRE INIT=0 starts reset_h LOW. First clk edge
+//                           samples ~reset_n which is LOW on power-up (the
+//                           parent DDC holds reset_n_400m low until the 2-
+//                           stage synchronizer releases), so reset_h goes
+//                           HIGH on cycle 1 and all DSPs see reset during
+//                           the following cycles. System is held in reset
+//                           for enough cycles that any initial register
+//                           state garbage is overwritten. ✅
+//   I4 (reset de-assertion):reset_h goes LOW one cycle AFTER reset_n_400m
+//                           goes HIGH. Downstream DSPs come out of reset on
+//                           the next clk edge after that. Total latency
+//                           from system reset release to first valid sample:
+//                           2 (sync chain) + 1 (reset_h reg) + 1 (first
+//                           DSP output) = 4 cycles at 400 MHz = 10 ns.
+//                           Negligible vs system reset assertion duration.
+// ----------------------------------------------------------------------------
+(* max_fanout = 50 *) reg reset_h = 1'b1;  // INIT=1'b1: registers start in reset state on power-up
+always @(posedge clk) reset_h <= ~reset_n;

 // Sign-extended input for integrator_0 C port (48-bit)
 wire [ACC_WIDTH-1:0] data_in_c = {{(ACC_WIDTH-18){data_in[17]}}, data_in};
@@ -699,10 +738,11 @@ initial begin
 end

 // Decimation control + monitoring (integrators are now DSP48E1 instances)
-// Sync reset: enables FDRE inference for better timing at 400 MHz.
-// Reset is already synchronous to clk via reset synchronizer in parent module.
+// Sync reset via reset_h (registered, max_fanout=50) — eliminates the shared
+// LUT1 inverter that previously fanned out to all fabric FDRE R pins plus
+// DSP48E1 RST pins (702 loads total). See "RESET FAN-OUT INVARIANT" at top.
 always @(posedge clk) begin
-    if (!reset_n) begin
+    if (reset_h) begin
        integrator_sampled <= 0;
        decimation_counter <= 0;
        data_valid_delayed <= 0;
@@ -755,9 +795,9 @@ always @(posedge clk) begin
 end

 // Pipeline the valid signal for comb section
-// Sync reset: matches decimation control block reset style.
+// Sync reset via reset_h — same replicated-register source as DSP48E1 RSTs.
 always @(posedge clk) begin
-    if (!reset_n) begin
+    if (reset_h) begin
        data_valid_comb <= 0;
        data_valid_comb_pipe <= 0;
        data_valid_comb_0_out <= 0;
@@ -792,7 +832,7 @@ end
 //   - Each stage: comb[i] = comb[i-1] - comb_delay[i][last]

 always @(posedge clk) begin
-    if (!reset_n) begin
+    if (reset_h) begin
        for (i = 0; i < STAGES; i = i + 1) begin
            comb[i] <= 0;
            for (j = 0; j < COMB_DELAY; j = j + 1) begin
@@ -32,8 +32,8 @@ the `USB_MODE` parameter in `radar_system_top.v`:

 | USB_MODE | Interface | Bus Width | Speed | Board Target |
 |----------|-----------|-----------|-------|--------------|
-| 0 (default) | FT601 (USB 3.0) | 32-bit | 100 MHz | 200T premium dev board |
-| 1 | FT2232H (USB 2.0) | 8-bit | 60 MHz | 50T production board |
+| 0 | FT601 (USB 3.0) | 32-bit | 100 MHz | 200T premium dev board |
+| 1 (default) | FT2232H (USB 2.0) | 8-bit | 60 MHz | 50T production board |

 ### How USB_MODE Works

@@ -72,7 +72,8 @@ The parameter is set via a **wrapper module** that overrides the default:
  ```

 - **200T dev board**: `radar_system_top` is used directly as the top module.
-  `USB_MODE` defaults to `0` (FT601). No wrapper needed.
+  `USB_MODE` defaults to `1` (FT2232H) since production is the primary target.
+  Override with `.USB_MODE(0)` for FT601 builds.

 ### RTL Files by USB Interface

@@ -158,7 +159,7 @@ The build scripts automatically select the correct top module and constraints:

 You do NOT need to set `USB_MODE` manually. The top module selection handles it:
 - `radar_system_top_50t` forces `USB_MODE=1` internally
- `radar_system_top` defaults to `USB_MODE=0`
+- `radar_system_top` defaults to `USB_MODE=1` (FT2232H, production default)

 ## How to Select Constraints in Vivado

@@ -190,9 +191,9 @@ read_xdc constraints/te0713_te0701_minimal.xdc
 | Target | Top module | USB_MODE | USB Interface | Notes |
 |--------|------------|----------|---------------|-------|
 | 50T Production (FTG256) | `radar_system_top_50t` | 1 | FT2232H (8-bit) | Wrapper sets USB_MODE=1, ties off FT601 |
-| 200T Dev (FBG484) | `radar_system_top` | 0 (default) | FT601 (32-bit) | No wrapper needed |
-| Trenz TE0712/TE0701 | `radar_system_top_te0712_dev` | 0 (default) | FT601 (32-bit) | Minimal bring-up wrapper |
-| Trenz TE0713/TE0701 | `radar_system_top_te0713_dev` | 0 (default) | FT601 (32-bit) | Alternate SoM wrapper |
+| 200T Dev (FBG484) | `radar_system_top` | 0 (override) | FT601 (32-bit) | Build script overrides default USB_MODE=1 |
+| Trenz TE0712/TE0701 | `radar_system_top_te0712_dev` | 0 (override) | FT601 (32-bit) | Minimal bring-up wrapper |
+| Trenz TE0713/TE0701 | `radar_system_top_te0713_dev` | 0 (override) | FT601 (32-bit) | Alternate SoM wrapper |

 ## Trenz Split Status

@@ -18,8 +18,23 @@
 #   Bank 35: VCCO = 3.3V (FT2232H USB 2.0 FIFO — 15 signals)
 #
 # DRC Fix History:
-#   - PLIO-9: Moved clk_120m_dac from C13 (N-type) to D13 (P-type MRCC).
-#     Clock inputs must use the P-type pin of a Multi-Region Clock-Capable pair.
+#   - PLIO-9 (REVERTED): Previously moved clk_120m_dac from C13 (N-type) to
+#     D13 (P-type MRCC) to satisfy the MRCC preference. However, a schematic
+#     audit (KiCad netlist export from the Eagle schematic, U42 pad->net map)
+#     revealed that D13 is UNCONNECTED on the physical PCB. The real
+#     /FPGA_DAC_CLOCK net from AD9523 OUT11 lands on C13 (IO_L11N_T1_SRCC_15,
+#     N-type). Moved back to C13 and added CLOCK_DEDICATED_ROUTE FALSE,
+#     matching the ft_clkout treatment on C4 (N-type MRCC).
+#   - Schematic audit added pin constraints for previously-unconstrained
+#     signals connected to the FPGA in hardware: ADC_OR_P/N (M6/N6, AD9484
+#     overflow flag), /FPGA_ADC_CLOCK_P/N (N11/N12, 400 MHz observation tap
+#     of the AD9523->AD9484 sample clock). Added to 50T wrapper as
+#     anchored-but-unused inputs to secure pin assignment and prevent
+#     accidental future contention; full RTL consumers are a follow-up.
+#   - PLIO-9 (original, historical): FT2232H CLKOUT routed to C4
+#     (IO_L12N_T1_MRCC_35, N-type). Clock inputs normally use P-type MRCC
+#     pins, but IBUFG works correctly on N-type. Demote PLIO-9 to warning
+#     in build script.
 #   - BIVC-1 / Place 30-372: Bank 14 must have a single VCCO. LVDS_25 forces
 #     VCCO=2.5V, so adc_pwdn was changed from LVCMOS33 to LVCMOS25 to match.
 #     IBUFDS input buffers are VCCO-independent. BIVC-1 also waived via
@@ -28,9 +43,6 @@
 #   - UCIO/NSTD: Unconstrained ports (FT601 ports inactive with USB_MODE=1,
 #     status/debug outputs have no physical pins). Handled with SEVERITY
 #     demotion + default IOSTANDARD.
-#   - PLIO-9: FT2232H CLKOUT routed to C4 (IO_L12N_T1_MRCC_35, N-type).
-#     Clock inputs normally use P-type MRCC pins, but IBUFG works correctly
-#     on N-type. Demote PLIO-9 to warning in build script.
 # ============================================================================

 # ============================================================================
@@ -66,19 +78,27 @@ set_property IOSTANDARD LVCMOS33 [get_ports {clk_100m}]
 create_clock -name clk_100m -period 10.0 [get_ports {clk_100m}]
 set_input_jitter [get_clocks clk_100m] 0.1

-# 120MHz DAC Clock (AD9523 OUT11 → FPGA_DAC_CLOCK → Bank 15 MRCC pin D13)
+# 120MHz DAC Clock (AD9523 OUT11 → /FPGA_DAC_CLOCK → Bank 15 pin C13)
 # NOTE: The physical DAC (U3, AD9708) receives its clock directly from the
 #       AD9523 via a separate net (DAC_CLOCK), NOT from the FPGA. The FPGA
 #       uses this clock input for internal DAC data timing only. The RTL port
-#       `dac_clk` is an output that assigns clk_120m directly — it has no
-#       separate physical pin on this board and should be removed from the
-#       RTL or left unconnected.
-# FIX: Moved from C13 (IO_L12N = N-type) to D13 (IO_L12P = P-type MRCC).
-#      Clock inputs must use the P-type pin of an MRCC pair (PLIO-9 DRC).
-set_property PACKAGE_PIN D13 [get_ports {clk_120m_dac}]
+#       `dac_clk` is an RTL output that assigns clk_120m directly. It has no
+#       physical pin on the 50T board and is left unconnected here. The port
+#       CANNOT be removed from the RTL because the 200T board uses it with
+#       ODDR clock forwarding (pin H17, see xc7a200t_fbg484.xdc).
+#
+# PIN: C13 is IO_L11N_T1_SRCC_15 (N-type SRCC). A prior commit attempted to
+# move this to D13 (MRCC P-type) to satisfy PLIO-9, but the schematic audit
+# showed D13 is UNCONNECTED on the PCB — the /FPGA_DAC_CLOCK net physically
+# lands on C13. Moving to D13 made the DAC clock input float. Restored to
+# C13 and forced CLOCK_DEDICATED_ROUTE FALSE (same mechanism as ft_clkout on
+# C4), which routes the IBUFG output through general fabric to a BUFG.
+set_property PACKAGE_PIN C13 [get_ports {clk_120m_dac}]
 set_property IOSTANDARD LVCMOS33 [get_ports {clk_120m_dac}]
 create_clock -name clk_120m_dac -period 8.333 [get_ports {clk_120m_dac}]
 set_input_jitter [get_clocks clk_120m_dac] 0.1
+# C13 is N-type SRCC (not dedicated-clock-capable); override the DRC check.
+set_property CLOCK_DEDICATED_ROUTE FALSE [get_nets {clk_120m_dac_IBUF}]

 # ADC DCO Clock (400MHz LVDS — AD9523 OUT5 → AD9484 → FPGA, Bank 14 MRCC)
 # NOTE: LVDS_25 is the only valid differential input standard on 7-series HR
@@ -224,7 +244,7 @@ set_property IOSTANDARD LVCMOS33 [get_ports {stm32_mixers_enable}]

 # DIG_5 = H11, DIG_6 = G12, DIG_7 = H12 — FPGA→STM32 status outputs
 # DIG_5: AGC saturation flag (PD13 on STM32)
-# DIG_6: reserved (PD14)
+# DIG_6: AGC enable flag (PD14) — mirrors FPGA host_agc_enable to STM32
 # DIG_7: reserved (PD15)
 set_property PACKAGE_PIN H11 [get_ports {gpio_dig5}]
 set_property PACKAGE_PIN G12 [get_ports {gpio_dig6}]
@@ -282,6 +302,45 @@ set_input_delay -clock [get_clocks adc_dco_p] -min 0.2 [get_ports {adc_d_p[*]}]
 set_input_delay -clock [get_clocks adc_dco_p] -max 1.0 -clock_fall [get_ports {adc_d_p[*]}] -add_delay
 set_input_delay -clock [get_clocks adc_dco_p] -min 0.2 -clock_fall [get_ports {adc_d_p[*]}] -add_delay

+# --------------------------------------------------------------------------
+# AD9484 Overflow / Out-Of-Range flag (schematic nets ADC_OR_P / ADC_OR_N)
+# --------------------------------------------------------------------------
+# AD9484 differential OR output on FPGA pads M6 (OR_P) / N6 (OR_N), Bank 14.
+# This is the AD9484's full-scale overflow indicator, useful for AGC /
+# gain-ranging feedback. The 50T RTL wrapper anchors this with an IBUFDS
+# (DONT_TOUCH) so the pads cannot be accidentally driven as outputs (which
+# would cause contention with the AD9484 driver). A future PR should wire
+# the buffered signal into the receive-path status flags.
+set_property PACKAGE_PIN M6 [get_ports {adc_or_p}]
+set_property PACKAGE_PIN N6 [get_ports {adc_or_n}]
+set_property IOSTANDARD LVDS_25 [get_ports {adc_or_p}]
+set_property IOSTANDARD LVDS_25 [get_ports {adc_or_n}]
+set_property DIFF_TERM TRUE [get_ports {adc_or_p}]
+
+# --------------------------------------------------------------------------
+# FPGA observation of AD9523->AD9484 sample clock (/FPGA_ADC_CLOCK_P/N)
+# --------------------------------------------------------------------------
+# AD9523 drives the AD9484 sample clock directly; the same differential
+# pair is tapped to FPGA pads N11 (P) / N12 (N), Bank 14, MRCC-capable.
+# This is an INPUT-ONLY tap (FPGA must never drive these pads — that would
+# contend with the AD9523 driver feeding the ADC). The 50T wrapper anchors
+# with IBUFDS + DONT_TOUCH so the pad assignment is preserved across all
+# synthesis/optimization stages. The buffered net is unconsumed for now;
+# create_clock and clock_groups are deferred until an RTL consumer exists
+# (see commented template below).
+set_property PACKAGE_PIN N11 [get_ports {fpga_adc_clock_p}]
+set_property PACKAGE_PIN N12 [get_ports {fpga_adc_clock_n}]
+set_property IOSTANDARD LVDS_25 [get_ports {fpga_adc_clock_p}]
+set_property IOSTANDARD LVDS_25 [get_ports {fpga_adc_clock_n}]
+set_property DIFF_TERM TRUE [get_ports {fpga_adc_clock_p}]
+# No create_clock here on purpose: the IBUFDS output is unconsumed (anchored
+# via DONT_TOUCH only), so declaring it as a clock would only generate
+# "clock has no registered destinations" warnings. When a follow-up PR adds
+# an actual consumer, add:
+#     create_clock -name fpga_adc_clock -period 2.5 [get_ports {fpga_adc_clock_p}]
+#     set_input_jitter [get_clocks fpga_adc_clock] 0.05
+#     set_clock_groups -asynchronous -group [get_clocks fpga_adc_clock] ...
+
 # ============================================================================
 # FT2232H USB 2.0 INTERFACE (Bank 35, VCCO=3.3V)
 # ============================================================================
@@ -332,6 +391,64 @@ set_property DRIVE 8 [get_ports {ft_data[*]}]

 # ft_clkout constrained above in CLOCK CONSTRAINTS section (C4, 60 MHz)

+# --------------------------------------------------------------------------
+# FT2232H Source-Synchronous Timing Constraints
+# --------------------------------------------------------------------------
+# FT2232H 245 Synchronous FIFO mode timing (60 MHz, period = 16.667 ns):
+#
+# FPGA Read Path (FT2232H drives data, FPGA samples):
+#   - Data valid before CLKOUT rising edge: t_vr(max) = 7.0 ns
+#   - Data hold after CLKOUT rising edge:   t_hr(min) = 0.0 ns
+#   - Input delay max = period - t_vr = 16.667 - 7.0 = 9.667 ns
+#   - Input delay min = t_hr = 0.0 ns
+#
+# FPGA Write Path (FPGA drives data, FT2232H samples):
+#   - Data setup before next CLKOUT rising: t_su = 5.0 ns
+#   - Data hold after CLKOUT rising:        t_hd = 0.0 ns
+#   - Board trace skew budget:               ~0.5 ns
+#   - Output delay max = t_su + trace_max = 5.0 + 0.5 = 5.5 ns
+#   - Output delay min = t_hd - trace_min = 0.0 - 0.0 = 0.0 ns
+#
+# NOTE: Historical XDC used 'period - t_su = 11.667 ns' for output_delay -max,
+# which is the wrong interpretation: set_output_delay takes the external setup
+# requirement (+trace), not the remaining timing budget. The old value forced
+# Vivado to close a path assuming FT2232H requires 11.667 ns of setup, which
+# it does not, and caused WNS=-5.350 ns failures on ft_data/ft_rd_n/ft_wr_n/
+# ft_oe_n/ft_siwu paths given the 5.513 ns clock insertion delay on the
+# non-dedicated C4 routing.
+# --------------------------------------------------------------------------
+
+# Input delays: FT2232H → FPGA (data bus and status signals)
+#
+# -min revision (Build N+1): was 0.0 ns, now 1.0 ns.
+# Rationale: set_input_delay -min is the EARLIEST time data can change at the
+# FPGA pin after the launch clock edge, i.e. FT2232H Tco_min + trace_min.
+# Setting -min 0.0 claimed data could change simultaneously with the clock
+# edge, which is pessimistically tight for hold analysis and caused a
+# -0.079 ns hold violation on ft_rxf_n → FSM_sequential_wr_state in Build N
+# (due to 2.895 ns clock insertion delay on non-dedicated C4 routing).
+# FT2232H Sync FIFO Tco is spec'd 1–4 ns; using 1.0 ns is conservative and
+# still covers worst-case silicon. Invariant preserved: hold_margin =
+# Tco_min + trace_min - clk_insertion_delay - Th_fpga ≥ 0.
+set_input_delay -clock [get_clocks ft_clkout] -max 9.667 [get_ports {ft_data[*]}]
+set_input_delay -clock [get_clocks ft_clkout] -min 1.0   [get_ports {ft_data[*]}]
+set_input_delay -clock [get_clocks ft_clkout] -max 9.667 [get_ports {ft_rxf_n}]
+set_input_delay -clock [get_clocks ft_clkout] -min 1.0   [get_ports {ft_rxf_n}]
+set_input_delay -clock [get_clocks ft_clkout] -max 9.667 [get_ports {ft_txe_n}]
+set_input_delay -clock [get_clocks ft_clkout] -min 1.0   [get_ports {ft_txe_n}]
+
+# Output delays: FPGA → FT2232H (control strobes and data bus when writing)
+set_output_delay -clock [get_clocks ft_clkout] -max 5.5 [get_ports {ft_data[*]}]
+set_output_delay -clock [get_clocks ft_clkout] -min 0.0 [get_ports {ft_data[*]}]
+set_output_delay -clock [get_clocks ft_clkout] -max 5.5 [get_ports {ft_rd_n}]
+set_output_delay -clock [get_clocks ft_clkout] -min 0.0 [get_ports {ft_rd_n}]
+set_output_delay -clock [get_clocks ft_clkout] -max 5.5 [get_ports {ft_wr_n}]
+set_output_delay -clock [get_clocks ft_clkout] -min 0.0 [get_ports {ft_wr_n}]
+set_output_delay -clock [get_clocks ft_clkout] -max 5.5 [get_ports {ft_oe_n}]
+set_output_delay -clock [get_clocks ft_clkout] -min 0.0 [get_ports {ft_oe_n}]
+set_output_delay -clock [get_clocks ft_clkout] -max 5.5 [get_ports {ft_siwu}]
+set_output_delay -clock [get_clocks ft_clkout] -min 0.0 [get_ports {ft_siwu}]
+
 # ============================================================================
 # STATUS / DEBUG OUTPUTS — NO PHYSICAL CONNECTIONS
 # ============================================================================
@@ -372,24 +489,42 @@ set_false_path -from [get_ports {stm32_mixers_enable}]
 set_false_path -from [get_cells reset_sync_reg[*]] -to [get_pins -filter {REF_PIN_NAME == CLR} -of_objects [get_cells -hierarchical -filter {PRIMITIVE_TYPE =~ REGISTER.*.*}]]

 # --------------------------------------------------------------------------
-# Clock Domain Crossing false paths
+# Clock Domain Crossing — asynchronous clock groups
+#
+# Rationale: prefer `set_clock_groups -asynchronous` over pairwise
+# `set_false_path -from CLK -to CLK`. The latter is an STA antipattern:
+# it disables *all* paths between the two domains, including the
+# synchronizer paths themselves and any future inadvertent crossings,
+# which can mask real CDC bugs that only show up at temperature/voltage
+# corners. Clock-groups is the idiomatic way to declare domains async
+# while still letting STA flag newly-introduced unrelated paths.
+#
+# Register-level false_paths (e.g. reset_sync_reg above) remain
+# appropriate — those restrict the waiver to specific, audited endpoints.
+#
+# Groups declared here mirror the pairwise false_paths that existed
+# previously; no new pair is declared async.
 # --------------------------------------------------------------------------

 # clk_100m ↔ adc_dco_p (400 MHz): DDC has internal CDC synchronizers
-set_false_path -from [get_clocks clk_100m] -to [get_clocks adc_dco_p]
-set_false_path -from [get_clocks adc_dco_p] -to [get_clocks clk_100m]
+set_clock_groups -asynchronous \
+    -group [get_clocks clk_100m] \
+    -group [get_clocks adc_dco_p]

 # clk_100m ↔ clk_120m_dac: CDC via synchronizers in radar_system_top
-set_false_path -from [get_clocks clk_100m] -to [get_clocks clk_120m_dac]
-set_false_path -from [get_clocks clk_120m_dac] -to [get_clocks clk_100m]
+set_clock_groups -asynchronous \
+    -group [get_clocks clk_100m] \
+    -group [get_clocks clk_120m_dac]

 # FT2232H CDC: clk_100m ↔ ft_clkout (60 MHz), toggle CDC in RTL
-set_false_path -from [get_clocks clk_100m] -to [get_clocks ft_clkout]
-set_false_path -from [get_clocks ft_clkout] -to [get_clocks clk_100m]
+set_clock_groups -asynchronous \
+    -group [get_clocks clk_100m] \
+    -group [get_clocks ft_clkout]

 # FT2232H CDC: clk_120m_dac ↔ ft_clkout (no direct crossing, but belt-and-suspenders)
-set_false_path -from [get_clocks clk_120m_dac] -to [get_clocks ft_clkout]
-set_false_path -from [get_clocks ft_clkout] -to [get_clocks clk_120m_dac]
+set_clock_groups -asynchronous \
+    -group [get_clocks clk_120m_dac] \
+    -group [get_clocks ft_clkout]

 # ============================================================================
 # PHYSICAL CONSTRAINTS
@@ -418,10 +553,10 @@ set_property BITSTREAM.CONFIG.UNUSEDPIN Pullup [current_design]
 # 4. JTAG: FPGA_TCK (L7), FPGA_TDI (N7), FPGA_TDO (N8), FPGA_TMS (M7).
 #    Dedicated pins — no XDC constraints needed.
 #
-# 5. dac_clk port: The RTL top module declares `dac_clk` as an output, but
-#    the physical board wires the DAC clock (AD9708 CLOCK pin) directly from
-#    the AD9523, not from the FPGA. This port should be removed from the RTL
-#    or left unconnected. It currently just assigns clk_120m_dac passthrough.
+# 5. dac_clk port: Not connected on the 50T board (DAC clocked directly from
+#    AD9523). The RTL port exists for 200T board compatibility, where the FPGA
+#    forwards the DAC clock via ODDR to pin H17 with generated clock and
+#    timing constraints (see xc7a200t_fbg484.xdc). Do NOT remove from RTL.
 #
 # ============================================================================
 # END OF CONSTRAINTS
@@ -53,46 +53,6 @@ reg [2:0] saturation_count;
 reg overflow_detected;
 reg [7:0] error_counter;

-// ============================================================================
-// 400 MHz Reset Synchronizer
-//
-// reset_n arrives from the 100 MHz domain (sys_reset_n from radar_system_top).
-// Using it directly as an async reset in the 400 MHz domain causes the reset
-// deassertion edge to violate timing: the 100 MHz flip-flop driving reset_n
-// has its output fanning out to 1156 registers across the FPGA in the 400 MHz
-// domain, requiring 18.243ns of routing (WNS = -18.081ns).
-//
-// Solution: 2-stage async-assert, sync-deassert reset synchronizer in the
-// 400 MHz domain. Reset assertion is immediate (asynchronous — combinatorial
-// path from reset_n to all 400 MHz registers). Reset deassertion is
-// synchronized to clk_400m rising edge, preventing metastability.
-//
-// All 400 MHz submodules (NCO, CIC, mixers, LFSR) use reset_n_400m.
-// All 100 MHz submodules (FIR, output stage) continue using reset_n directly
-// (already synchronized to 100 MHz at radar_system_top level).
-// ============================================================================
-(* ASYNC_REG = "TRUE" *) reg [1:0] reset_sync_400m;
-(* max_fanout = 50 *) wire reset_n_400m = reset_sync_400m[1];
-
-// Active-high reset for DSP48E1 RST ports (avoids LUT1 inverter fan-out)
-(* max_fanout = 50 *) reg reset_400m;
-
-always @(posedge clk_400m or negedge reset_n) begin
-    if (!reset_n) begin
-        reset_sync_400m <= 2'b00;
-        reset_400m      <= 1'b1;
-    end else begin
-        reset_sync_400m <= {reset_sync_400m[0], 1'b1};
-        reset_400m      <= ~reset_sync_400m[1];
-    end
-end
-
-// CDC synchronization for control signals (2-stage synchronizers)
-(* ASYNC_REG = "TRUE" *) reg [1:0] mixers_enable_sync_chain;
-(* ASYNC_REG = "TRUE" *) reg [1:0] force_saturation_sync_chain;
-wire mixers_enable_sync;
-wire force_saturation_sync;
-
 // Debug monitoring signals
 reg [31:0] sample_counter;
 wire signed [17:0] debug_mixed_i_trunc;
@@ -130,8 +90,6 @@ reg baseband_valid_reg;
 wire [7:0] phase_dither_bits;
 reg [31:0] phase_inc_dithered;

-
-
 // ============================================================================
 // Debug Signal Assignments
 // ============================================================================
@@ -142,13 +100,66 @@ assign debug_mixed_i_trunc = mixed_i[25:8];
 assign debug_mixed_q_trunc = mixed_q[25:8];

 // ============================================================================
-// Clock Domain Crossing for Control Signals (2-stage synchronizers)
+// 400 MHz Reset Synchronizer
+//
+// reset_n arrives from the 100 MHz domain (sys_reset_n from radar_system_top).
+// Using it directly as an async reset in the 400 MHz domain causes the reset
+// deassertion edge to violate timing: the 100 MHz flip-flop driving reset_n
+// has its output fanning out to 1156 registers across the FPGA in the 400 MHz
+// domain, requiring 18.243ns of routing (WNS = -18.081ns).
+//
+// Solution: 2-stage async-assert, sync-deassert reset synchronizer in the
+// 400 MHz domain. Reset assertion is immediate (asynchronous — combinatorial
+// path from reset_n to all 400 MHz registers). Reset deassertion is
+//
+// reset_400m   : ACTIVE-HIGH registered reset with (* max_fanout = 50 *).
+//                This is THE signal fed to every synchronous 400 MHz FDRE
+//                and every DSP48E1 RST pin in this module and its children
+//                (NCO, CIC, LFSR). Vivado replicates the register (~14
+//                copies) so each replica drives ≈50 loads regionally,
+//                eliminating the single-LUT1 / 702-load net that caused
+//                WNS=-0.626 ns in Build N.
+//
+// System-level invariants preserved:
+//   I1  Reset assertion propagates to all 400 MHz regs within ≤3 clk edges
+//       (2 sync + 1 replicated-reg fanout).  At 400 MHz = 7.5 ns << any
+//       system-level reset assertion duration.
+//   I2  Reset de-assertion is always synchronous to clk_400m (via
+//       reset_sync_400m), never glitches.
+//   I3  DSP48E1 RST pins are all fed from Q of a register — glitch-free.
+//   I4  No new CDC introduced: reset_400m is entirely in clk_400m domain.
+//   I5  Power-up: reset_n is asserted externally and mmcm_locked is low;
+//       reset_sync_400m stays 2'b00, reset_400m stays 1'b1, downstream
+//       FDREs stay cleared. Safe.
 // ============================================================================
+(* ASYNC_REG = "TRUE" *) reg [1:0] reset_sync_400m = 2'b00;
+(* max_fanout = 50 *) wire reset_n_400m = reset_sync_400m[1];
+
+// Active-high replicated reset for all synchronous 400 MHz consumers
+(* max_fanout = 50 *) reg reset_400m = 1'b1;
+
+always @(posedge clk_400m or negedge reset_n) begin
+    if (!reset_n) begin
+        reset_sync_400m <= 2'b00;
+        reset_400m      <= 1'b1;
+    end else begin
+        reset_sync_400m <= {reset_sync_400m[0], 1'b1};
+        reset_400m      <= ~reset_sync_400m[1];
+    end
+end
+
+// CDC synchronization for control signals (2-stage synchronizers)
+(* ASYNC_REG = "TRUE" *) reg [1:0] mixers_enable_sync_chain;
+(* ASYNC_REG = "TRUE" *) reg [1:0] force_saturation_sync_chain;
+wire mixers_enable_sync;
+wire force_saturation_sync;
 assign mixers_enable_sync = mixers_enable_sync_chain[1];
 assign force_saturation_sync = force_saturation_sync_chain[1];

-always @(posedge clk_400m or negedge reset_n_400m) begin
-    if (!reset_n_400m) begin
+// Sync reset via reset_400m (replicated, max_fanout=50). Was async on
+// reset_n_400m — see "400 MHz RESET DISTRIBUTION" comment above.
+always @(posedge clk_400m) begin
+    if (reset_400m) begin
        mixers_enable_sync_chain <= 2'b00;
        force_saturation_sync_chain <= 2'b00;
    end else begin
@@ -160,8 +171,8 @@ end
 // ============================================================================
 // Sample Counter and Debug Monitoring
 // ============================================================================
-always @(posedge clk_400m or negedge reset_n_400m) begin
-    if (!reset_n_400m || reset_monitors) begin
+always @(posedge clk_400m) begin
+    if (reset_400m || reset_monitors) begin
        sample_counter <= 0;
        error_counter <= 0;
    end else if (adc_data_valid_i && adc_data_valid_q ) begin
@@ -189,8 +200,8 @@ lfsr_dither_enhanced #(
 localparam PHASE_INC_120MHZ = 32'h4CCCCCCD;

 // Apply dithering to reduce spurious tones (registered for 400 MHz timing)
-always @(posedge clk_400m or negedge reset_n_400m) begin
-    if (!reset_n_400m)
+always @(posedge clk_400m) begin
+    if (reset_400m)
        phase_inc_dithered <= PHASE_INC_120MHZ;
    else
        phase_inc_dithered <= PHASE_INC_120MHZ + {24'b0, phase_dither_bits};
@@ -229,8 +240,8 @@ assign adc_signed_w = {1'b0, adc_data, {(MIXER_WIDTH-ADC_WIDTH-1){1'b0}}} -
                      {1'b0, {ADC_WIDTH{1'b1}}, {(MIXER_WIDTH-ADC_WIDTH-1){1'b0}}} / 2;

 // Valid pipeline: 5-stage shift register (1 NCO pipe + 3 DSP48E1 AREG+MREG+PREG + 1 retiming)
-always @(posedge clk_400m or negedge reset_n_400m) begin
-    if (!reset_n_400m) begin
+always @(posedge clk_400m) begin
+    if (reset_400m) begin
        dsp_valid_pipe <= 5'b00000;
    end else begin
        dsp_valid_pipe <= {dsp_valid_pipe[3:0], (nco_ready && adc_data_valid_i && adc_data_valid_q)};
@@ -246,8 +257,8 @@ reg signed [MIXER_WIDTH+NCO_WIDTH-1:0] mult_i_internal, mult_q_internal;  // Mod
 reg signed [MIXER_WIDTH+NCO_WIDTH-1:0] mult_i_reg, mult_q_reg;            // Models PREG

 // Stage 0: NCO pipeline — breaks long NCO→DSP route (matches synthesis fabric registers)
-always @(posedge clk_400m or negedge reset_n_400m) begin
-    if (!reset_n_400m) begin
+always @(posedge clk_400m) begin
+    if (reset_400m) begin
        cos_nco_pipe <= 0;
        sin_nco_pipe <= 0;
    end else begin
@@ -257,8 +268,8 @@ always @(posedge clk_400m or negedge reset_n_400m) begin
 end

 // Stage 1: AREG/BREG equivalent (uses pipelined NCO outputs)
-always @(posedge clk_400m or negedge reset_n_400m) begin
-    if (!reset_n_400m) begin
+always @(posedge clk_400m) begin
+    if (reset_400m) begin
        adc_signed_reg <= 0;
        cos_pipe_reg <= 0;
        sin_pipe_reg <= 0;
@@ -270,8 +281,8 @@ always @(posedge clk_400m or negedge reset_n_400m) begin
 end

 // Stage 2: MREG equivalent
-always @(posedge clk_400m or negedge reset_n_400m) begin
-    if (!reset_n_400m) begin
+always @(posedge clk_400m) begin
+    if (reset_400m) begin
        mult_i_internal <= 0;
        mult_q_internal <= 0;
    end else begin
@@ -281,8 +292,8 @@ always @(posedge clk_400m or negedge reset_n_400m) begin
 end

 // Stage 3: PREG equivalent
-always @(posedge clk_400m or negedge reset_n_400m) begin
-    if (!reset_n_400m) begin
+always @(posedge clk_400m) begin
+    if (reset_400m) begin
        mult_i_reg <= 0;
        mult_q_reg <= 0;
    end else begin
@@ -292,8 +303,8 @@ always @(posedge clk_400m or negedge reset_n_400m) begin
 end

 // Stage 4: Post-DSP retiming register (matches synthesis path)
-always @(posedge clk_400m or negedge reset_n_400m) begin
-    if (!reset_n_400m) begin
+always @(posedge clk_400m) begin
+    if (reset_400m) begin
        mult_i_retimed <= 0;
        mult_q_retimed <= 0;
    end else begin
@@ -311,8 +322,8 @@ wire [47:0] dsp_p_i, dsp_p_q;
 // (1.505ns routing observed in Build 26). These fabric registers are placed
 // near the DSP by the placer, splitting the route into two shorter segments.
 // DONT_TOUCH on the reg declaration (above) prevents absorption/retiming.
-always @(posedge clk_400m or negedge reset_n_400m) begin
-    if (!reset_n_400m) begin
+always @(posedge clk_400m) begin
+    if (reset_400m) begin
        cos_nco_pipe <= 0;
        sin_nco_pipe <= 0;
    end else begin
@@ -329,11 +340,10 @@ DSP48E1 #(
    .USE_DPORT("FALSE"),
    .USE_MULT("MULTIPLY"),
    .USE_SIMD("ONE48"),
-    // Pipeline register attributes — all enabled for max timing
    .AREG(1),
    .BREG(1),
    .MREG(1),
-    .PREG(1),           // P register enabled — absorbs CLK→P delay for timing closure
+    .PREG(1),
    .ADREG(0),
    .ACASCREG(1),
    .BCASCREG(1),
@@ -344,7 +354,6 @@ DSP48E1 #(
    .DREG(0),
    .INMODEREG(0),
    .OPMODEREG(0),
-    // Pattern detector (unused)
    .AUTORESET_PATDET("NO_RESET"),
    .MASK(48'h3fffffffffff),
    .PATTERN(48'h000000000000),
@@ -496,8 +505,8 @@ wire signed [MIXER_WIDTH+NCO_WIDTH-1:0] mult_q_reg = dsp_p_q[MIXER_WIDTH+NCO_WID
 // Stage 4: Post-DSP retiming register — breaks DSP48E1 CLK→P to fabric path
 // Without this, the DSP output prop delay (1.866ns) + routing (0.515ns) exceeds
 // the 2.500ns clock period at slow process corner
-always @(posedge clk_400m or negedge reset_n_400m) begin
-    if (!reset_n_400m) begin
+always @(posedge clk_400m) begin
+    if (reset_400m) begin
        mult_i_retimed <= 0;
        mult_q_retimed <= 0;
    end else begin
@@ -513,8 +522,8 @@ end
 // force_saturation mux is intentionally AFTER the DSP48E1 output to avoid
 // polluting the critical input path with extra logic
 // ============================================================================
-always @(posedge clk_400m or negedge reset_n_400m) begin
-    if (!reset_n_400m) begin
+always @(posedge clk_400m) begin
+    if (reset_400m) begin
        mixed_i <= 0;
        mixed_q <= 0;
        mixed_valid <= 0;
@@ -759,8 +768,17 @@ generate
    end
 endgenerate

-always @(posedge clk or negedge reset_n) begin
-    if (!reset_n) begin
+// ============================================================================
+// RESET FAN-OUT INVARIANT: registered active-high reset with max_fanout=50.
+// See cic_decimator_4x_enhanced.v for full reasoning. reset_n here is driven
+// by the parent DDC's reset_n_400m (already synchronized to clk_400m), so
+// sync reset on the LFSR is safe. INIT=1'b1 holds LFSR in reset on power-up.
+// ============================================================================
+(* max_fanout = 50 *) reg reset_h = 1'b1;
+always @(posedge clk) reset_h <= ~reset_n;
+
+always @(posedge clk) begin
+    if (reset_h) begin
        lfsr_reg <= {DITHER_WIDTH{1'b1}};  // Non-zero initial state
        cycle_counter <= 0;
        lock_detected <= 0;
@@ -59,6 +59,25 @@ reg [1:0] quadrant_reg2;                 // Pass-through for Stage 5 MUX
 // Valid pipeline: tracks 6-stage latency
 reg [5:0] valid_pipe;

+// ============================================================================
+// RESET FAN-OUT INVARIANT (Build N+1 fix for WNS=-0.626ns at 400 MHz):
+// ============================================================================
+// reset_h is an ACTIVE-HIGH, REGISTERED copy of ~reset_n with (* max_fanout=50 *).
+// Vivado replicates this register (14+ copies) so each copy drives ≈50 loads
+// regionally, avoiding the single-LUT1 / 702-load net that caused timing
+// failure in Build N. It feeds:
+//   - DSP48E1 RSTP/RSTC on the phase-accumulator DSP (below)
+//   - All pipeline-stage fabric FDREs (synchronous reset)
+// Invariants (see cic_decimator_4x_enhanced.v for full reasoning):
+//   I1 correctness:      reset_h == ~reset_n one cycle later
+//   I2 glitch-free:      registered output
+//   I3 power-up safe:    INIT=1'b1 holds all downstream in reset until first
+//                        valid clock edge; reset_n is low on power-up anyway
+//   I4 de-assert lat.:   +1 cycle vs. direct async; negligible at 400 MHz
+// ============================================================================
+(* max_fanout = 50 *) reg reset_h = 1'b1;
+always @(posedge clk_400m) reset_h <= ~reset_n;
+
 // Use only the top 8 bits for LUT addressing (256-entry LUT equivalent)
 wire [7:0] lut_address = phase_with_offset[31:24];

@@ -135,8 +154,8 @@ wire [15:0] cos_abs_w = sin_lut[63 - lut_index_pipe_cos];
 // Stage 2: phase_with_offset adds phase offset
 reg [31:0] phase_accumulator;

-always @(posedge clk_400m or negedge reset_n) begin
-    if (!reset_n) begin
+always @(posedge clk_400m) begin
+    if (reset_h) begin
        phase_accumulator <= 32'h00000000;
        phase_accum_reg   <= 32'h00000000;
        phase_with_offset <= 32'h00000000;
@@ -190,8 +209,8 @@ DSP48E1 #(
    .RSTA(1'b0),
    .RSTB(1'b0),
    .RSTM(1'b0),
-    .RSTP(!reset_n),             // Reset P register (phase accumulator) on !reset_n
-    .RSTC(!reset_n),             // Reset C register (tuning word) on !reset_n
+    .RSTP(reset_h),              // Reset P register (phase accumulator) — registered, max_fanout=50
+    .RSTC(reset_h),              // Reset C register (tuning word)       — registered, max_fanout=50
    .RSTALLCARRYIN(1'b0),
    .RSTALUMODE(1'b0),
    .RSTCTRL(1'b0),
@@ -245,8 +264,8 @@ DSP48E1 #(
 // Stage 1: Capture DSP48E1 P output into fabric register
 // Stage 2: Add phase offset to captured value
 // Split into two registered stages to break DSP48E1.P→CARRY4 critical path
-always @(posedge clk_400m or negedge reset_n) begin
-    if (!reset_n) begin
+always @(posedge clk_400m) begin
+    if (reset_h) begin
        phase_accum_reg   <= 32'h00000000;
        phase_with_offset <= 32'h00000000;
    end else if (phase_valid) begin
@@ -264,8 +283,8 @@ end
 //           Only 2 registers driven (lut_index_pipe + quadrant_pipe)
 //           Minimal fanout → short routes → easy timing
 // ============================================================================
-always @(posedge clk_400m or negedge reset_n) begin
-    if (!reset_n) begin
+always @(posedge clk_400m) begin
+    if (reset_h) begin
        lut_index_pipe_sin <= 6'b000000;
        lut_index_pipe_cos <= 6'b000000;
        quadrant_pipe      <= 2'b00;
@@ -281,8 +300,8 @@ end
 //           Registered address → combinational LUT6 read → register
 //           Only 1 logic level (LUT6), trivial timing
 // ============================================================================
-always @(posedge clk_400m or negedge reset_n) begin
-    if (!reset_n) begin
+always @(posedge clk_400m) begin
+    if (reset_h) begin
        sin_abs_reg <= 16'h0000;
        cos_abs_reg <= 16'h7FFF;
        quadrant_reg <= 2'b00;
@@ -298,8 +317,8 @@ end
 //          CARRY4 x4 chain has registered inputs — easily fits in 2.5ns
 //          Also pass through abs values and quadrant for Stage 5
 // ============================================================================
-always @(posedge clk_400m or negedge reset_n) begin
-    if (!reset_n) begin
+always @(posedge clk_400m) begin
+    if (reset_h) begin
        sin_neg_reg <= 16'h0000;
        cos_neg_reg <= -16'h7FFF;
        sin_abs_reg2 <= 16'h0000;
@@ -318,8 +337,8 @@ end
 // Stage 5: Quadrant sign application → final sin/cos output
 //          Uses pre-computed negated values from Stage 4 — pure MUX, no arithmetic
 // ============================================================================
-always @(posedge clk_400m or negedge reset_n) begin
-    if (!reset_n) begin
+always @(posedge clk_400m) begin
+    if (reset_h) begin
        sin_out <= 16'h0000;
        cos_out <= 16'h7FFF;
    end else if (valid_pipe[4]) begin
@@ -347,8 +366,8 @@ end
 // ============================================================================
 // Valid pipeline and dds_ready (6-stage latency)
 // ============================================================================
-always @(posedge clk_400m or negedge reset_n) begin
-    if (!reset_n) begin
+always @(posedge clk_400m) begin
+    if (reset_h) begin
        valid_pipe <= 6'b000000;
        dds_ready <= 1'b0;
    end else begin
@@ -130,7 +130,7 @@ module radar_system_top (
    // FPGA→STM32 GPIO outputs (DIG_5..DIG_7 on 50T board)
    // Used by STM32 outer AGC loop to read saturation state without USB polling.
    output wire gpio_dig5,          // DIG_5 (H11→PD13): AGC saturation flag (1=clipping detected)
-    output wire gpio_dig6,          // DIG_6 (G12→PD14): reserved (tied low)
+    output wire gpio_dig6,          // DIG_6 (G12→PD14): AGC enable flag (mirrors host_agc_enable)
    output wire gpio_dig7           // DIG_7 (H12→PD15): reserved (tied low)
 );

@@ -142,7 +142,7 @@ module radar_system_top (
 parameter USE_LONG_CHIRP = 1'b1;          // Default to long chirp
 parameter DOPPLER_ENABLE = 1'b1;           // Enable Doppler processing
 parameter USB_ENABLE = 1'b1;               // Enable USB data transfer
-parameter USB_MODE = 0;                    // 0=FT601 (32-bit, 200T), 1=FT2232H (8-bit, 50T)
+parameter USB_MODE = 1;                    // 0=FT601 (32-bit, 200T), 1=FT2232H (8-bit, 50T production default)

 // ============================================================================
 // INTERNAL SIGNALS
@@ -1037,9 +1037,11 @@ assign system_status = status_reg;
 // ============================================================================
 // DIG_5: AGC saturation flag — high when per-frame saturation_count > 0.
 //        STM32 reads PD13 to detect clipping and adjust ADAR1000 VGA gain.
-// DIG_6, DIG_7: Reserved (tied low for future use).
+// DIG_6: AGC enable flag — mirrors host_agc_enable so STM32 outer-loop AGC
+//        tracks the FPGA register as single source of truth.
+// DIG_7: Reserved (tied low for future use).
 assign gpio_dig5 = (rx_agc_saturation_count != 8'd0);
-assign gpio_dig6 = 1'b0;
+assign gpio_dig6 = host_agc_enable;
 assign gpio_dig7 = 1'b0;

 // ============================================================================
@@ -62,6 +62,20 @@ module radar_system_top_50t (
    input wire adc_dco_n,
    output wire adc_pwdn,

+    // ----- AD9484 overflow flag (differential) -----
+    // Schematic pads M6 (OR_P) / N6 (OR_N). Anchored-only for now; a future
+    // PR will wire this into the receive-path status flags for AGC feedback.
+    input wire adc_or_p,
+    input wire adc_or_n,
+
+    // ----- Tap of AD9523 -> AD9484 sample clock (differential) -----
+    // Schematic pads N11 (P) / N12 (N). Must remain input-only — driving
+    // these pads as outputs would contend with the AD9523 driver feeding
+    // the ADC. Anchored with an IBUFDS (DONT_TOUCH) below; buffered net is
+    // unconsumed pending a follow-up PR.
+    input wire fpga_adc_clock_p,
+    input wire fpga_adc_clock_n,
+
    // ===== STM32 Control (Bank 15: 3.3V) =====
    input wire stm32_new_chirp,
    input wire stm32_new_elevation,
@@ -84,6 +98,38 @@ module radar_system_top_50t (
    output wire gpio_dig7             // DIG_7 (H12→PD15): reserved
 );

+    // =====================================================================
+    // Anchored-but-unused schematic inputs (secured via IBUFDS + DONT_TOUCH)
+    // =====================================================================
+    // Without these buffer instantiations, synthesis would remove the
+    // orphan input ports (UCIO / NSTD warnings) and the XDC pin constraints
+    // would fail to bind. DONT_TOUCH forces Vivado to retain the buffer
+    // primitives and their package-pin connections across all optimization
+    // stages. The buffered nets are intentionally left unconsumed here;
+    // they will be wired into the RTL in a follow-up PR once the ADC
+    // status-flag and sample-clock-tap features are implemented.
+    (* DONT_TOUCH = "TRUE" *) wire adc_or_buf;
+    (* DONT_TOUCH = "TRUE" *) IBUFDS #(
+        .DIFF_TERM   ("TRUE"),
+        .IBUF_LOW_PWR("FALSE"),
+        .IOSTANDARD  ("LVDS_25")
+    ) u_ibufds_adc_or (
+        .O  (adc_or_buf),
+        .I  (adc_or_p),
+        .IB (adc_or_n)
+    );
+
+    (* DONT_TOUCH = "TRUE" *) wire fpga_adc_clock_buf;
+    (* DONT_TOUCH = "TRUE" *) IBUFDS #(
+        .DIFF_TERM   ("TRUE"),
+        .IBUF_LOW_PWR("FALSE"),
+        .IOSTANDARD  ("LVDS_25")
+    ) u_ibufds_fpga_adc_clk (
+        .O  (fpga_adc_clock_buf),
+        .I  (fpga_adc_clock_p),
+        .IB (fpga_adc_clock_n)
+    );
+
    // ===== Tie-off wires for unconstrained FT601 inputs (inactive with USB_MODE=1) =====
    wire        ft601_txe_tied    = 1'b0;
    wire        ft601_rxf_tied    = 1'b0;
@@ -138,7 +138,12 @@ usb_data_interface usb_inst (
    .status_range_mode(2'b01),
    .status_self_test_flags(5'b11111),
    .status_self_test_detail(8'hA5),
-    .status_self_test_busy(1'b0)
+    .status_self_test_busy(1'b0),
+    // AGC status: tie off with benign defaults (no AGC on dev board)
+    .status_agc_current_gain(4'd0),
+    .status_agc_peak_magnitude(8'd0),
+    .status_agc_saturation_count(8'd0),
+    .status_agc_enable(1'b0)
 );

 endmodule
@@ -70,6 +70,7 @@ PROD_RTL=(
    xfft_16.v
    fft_engine.v
    usb_data_interface.v
+    usb_data_interface_ft2232h.v
    edge_detector.v
    radar_mode_controller.v
    rx_gain_control.v
@@ -86,6 +87,33 @@ EXTRA_RTL=(
    frequency_matched_filter.v
 )

+# ---------------------------------------------------------------------------
+# Shared RTL file lists for integration / system tests
+# Centralised here so a new module only needs adding once.
+# ---------------------------------------------------------------------------
+
+# Receiver chain (used by golden generate/compare tests)
+RECEIVER_RTL=(
+    radar_receiver_final.v
+    radar_mode_controller.v
+    tb/ad9484_interface_400m_stub.v
+    ddc_400m.v nco_400m_enhanced.v cic_decimator_4x_enhanced.v
+    cdc_modules.v fir_lowpass.v ddc_input_interface.v
+    chirp_memory_loader_param.v latency_buffer.v
+    matched_filter_multi_segment.v matched_filter_processing_chain.v
+    range_bin_decimator.v doppler_processor.v xfft_16.v fft_engine.v
+    rx_gain_control.v mti_canceller.v
+)
+
+# Full system top (receiver chain + TX + USB + detection + self-test)
+SYSTEM_RTL=(
+    radar_system_top.v
+    radar_transmitter.v dac_interface_single.v plfm_chirp_controller.v
+    "${RECEIVER_RTL[@]}"
+    usb_data_interface.v usb_data_interface_ft2232h.v edge_detector.v
+    cfar_ca.v fpga_self_test.v
+)
+
 # ---- Layer A: iverilog -Wall compilation ----
 run_lint_iverilog() {
    local label="$1"
@@ -219,26 +247,9 @@ run_lint_static() {
        fi
    done

-    # --- Single-line regex checks across all production RTL ---
-    for f in "$@"; do
-        [[ -f "$f" ]] || continue
-        case "$f" in tb/*) continue ;; esac
-
-        local linenum=0
-        while IFS= read -r line; do
-            linenum=$((linenum + 1))
-
-            # CHECK 5: $readmemh / $readmemb in synthesizable code
-            # (Only valid in simulation blocks — flag if outside `ifdef SIMULATION)
-            # This is hard to check line-by-line without tracking ifdefs.
-            # Skip for v1.
-
-            # CHECK 6: Unused `include files (informational only)
-            # Skip for v1.
-
-            :  # placeholder — prevents empty loop body
-        done < "$f"
-    done
+    # CHECK 5 ($readmemh in synth code) and CHECK 6 (unused includes)
+    # require multi-line ifdef tracking / cross-file analysis. Not feasible
+    # with line-by-line regex. Omitted — use Vivado lint instead.

    if [[ "$err_count" -gt 0 ]]; then
        echo -e "${RED}FAIL${NC} ($err_count errors, $warn_count warnings)"
@@ -420,57 +431,36 @@ if [[ "$QUICK" -eq 0 ]]; then
    run_test "Receiver (golden generate)" \
        tb/tb_rx_golden_reg.vvp \
        -DGOLDEN_GENERATE \
-        tb/tb_radar_receiver_final.v radar_receiver_final.v \
-        radar_mode_controller.v tb/ad9484_interface_400m_stub.v \
-        ddc_400m.v nco_400m_enhanced.v cic_decimator_4x_enhanced.v \
-        cdc_modules.v fir_lowpass.v ddc_input_interface.v \
-        chirp_memory_loader_param.v latency_buffer.v \
-        matched_filter_multi_segment.v matched_filter_processing_chain.v \
-        range_bin_decimator.v doppler_processor.v xfft_16.v fft_engine.v \
-        rx_gain_control.v mti_canceller.v
+        tb/tb_radar_receiver_final.v "${RECEIVER_RTL[@]}"

    # Golden compare
    run_test "Receiver (golden compare)" \
        tb/tb_rx_compare_reg.vvp \
-        tb/tb_radar_receiver_final.v radar_receiver_final.v \
-        radar_mode_controller.v tb/ad9484_interface_400m_stub.v \
-        ddc_400m.v nco_400m_enhanced.v cic_decimator_4x_enhanced.v \
-        cdc_modules.v fir_lowpass.v ddc_input_interface.v \
-        chirp_memory_loader_param.v latency_buffer.v \
-        matched_filter_multi_segment.v matched_filter_processing_chain.v \
-        range_bin_decimator.v doppler_processor.v xfft_16.v fft_engine.v \
-        rx_gain_control.v mti_canceller.v
+        tb/tb_radar_receiver_final.v "${RECEIVER_RTL[@]}"

    # Full system top (monitoring-only, legacy)
    run_test "System Top (radar_system_tb)" \
        tb/tb_system_reg.vvp \
-        tb/radar_system_tb.v radar_system_top.v \
-        radar_transmitter.v dac_interface_single.v plfm_chirp_controller.v \
-        radar_receiver_final.v tb/ad9484_interface_400m_stub.v \
-        ddc_400m.v nco_400m_enhanced.v cic_decimator_4x_enhanced.v \
-        cdc_modules.v fir_lowpass.v ddc_input_interface.v \
-        chirp_memory_loader_param.v latency_buffer.v \
-        matched_filter_multi_segment.v matched_filter_processing_chain.v \
-        range_bin_decimator.v doppler_processor.v xfft_16.v fft_engine.v \
-        usb_data_interface.v edge_detector.v radar_mode_controller.v \
-        rx_gain_control.v cfar_ca.v mti_canceller.v fpga_self_test.v
+        tb/radar_system_tb.v "${SYSTEM_RTL[@]}"

    # E2E integration (46 strict checks: TX, RX, USB R/W, CDC, safety, reset)
    run_test "System E2E (tb_system_e2e)" \
        tb/tb_system_e2e_reg.vvp \
-        tb/tb_system_e2e.v radar_system_top.v \
-        radar_transmitter.v dac_interface_single.v plfm_chirp_controller.v \
-        radar_receiver_final.v tb/ad9484_interface_400m_stub.v \
-        ddc_400m.v nco_400m_enhanced.v cic_decimator_4x_enhanced.v \
-        cdc_modules.v fir_lowpass.v ddc_input_interface.v \
-        chirp_memory_loader_param.v latency_buffer.v \
-        matched_filter_multi_segment.v matched_filter_processing_chain.v \
-        range_bin_decimator.v doppler_processor.v xfft_16.v fft_engine.v \
-        usb_data_interface.v edge_detector.v radar_mode_controller.v \
-        rx_gain_control.v cfar_ca.v mti_canceller.v fpga_self_test.v
+        tb/tb_system_e2e.v "${SYSTEM_RTL[@]}"
+
+    # USB_MODE=1 (FT2232H production) variants of system tests
+    run_test "System Top USB_MODE=1 (FT2232H)" \
+        tb/tb_system_ft2232h_reg.vvp \
+        -DUSB_MODE_1 \
+        tb/radar_system_tb.v "${SYSTEM_RTL[@]}"
+
+    run_test "System E2E USB_MODE=1 (FT2232H)" \
+        tb/tb_system_e2e_ft2232h_reg.vvp \
+        -DUSB_MODE_1 \
+        tb/tb_system_e2e.v "${SYSTEM_RTL[@]}"
 else
    echo "  (skipped receiver golden + system top + E2E — use without --quick)"
-    SKIP=$((SKIP + 4))
+    SKIP=$((SKIP + 6))
 fi

 echo ""
@@ -108,6 +108,9 @@ add_files -fileset constrs_1 -norecurse [file join $project_root "constraints" "

 set_property top $top_module [current_fileset]
 set_property verilog_define {FFT_XPM_BRAM} [current_fileset]
+# Override USB_MODE to 0 (FT601) for 200T premium board.
+# The RTL default is USB_MODE=1 (FT2232H, production 50T).
+set_property generic {USB_MODE=0} [current_fileset]

 # ==============================================================================
 # 2. Synthesis
@@ -291,9 +291,12 @@ class Mixer:
        Convert 8-bit unsigned ADC to 18-bit signed.
        RTL: adc_signed_w = {1'b0, adc_data, {9{1'b0}}} -
                            {1'b0, {8{1'b1}}, {9{1'b0}}} / 2
-        = (adc_data << 9) - (0xFF << 9) / 2
-        = (adc_data << 9) - (0xFF << 8)  [integer division]
-        = (adc_data << 9) - 0x7F80
+
+        Verilog '/' binds tighter than '-', so the division applies
+        only to the second concatenation:
+            {1'b0, 8'hFF, 9'b0} = 0x1FE00
+            0x1FE00 / 2 = 0xFF00 = 65280
+        Result: (adc_data << 9) - 0xFF00
        """
        adc_data_8bit = adc_data_8bit & 0xFF
        # {1'b0, adc_data, 9'b0} = adc_data << 9, zero-padded to 18 bits
@@ -290,9 +290,9 @@ def run_ddc(adc_samples):
    for n in range(n_samples):
        # ADC sign conversion: RTL does offset binary → signed 18-bit
        # adc_signed_w = {1'b0, adc_data, 9'b0} - {1'b0, 8'hFF, 9'b0}/2
-        # Simplified: center around zero, scale to 18-bit
+        # Exact: (adc_val << 9) - 0xFF00, where 0xFF00 = {1'b0,8'hFF,9'b0}/2
        adc_val = int(adc_samples[n])
-        adc_signed = (adc_val - 128) << 9  # Approximate RTL sign conversion to 18-bit
+        adc_signed = (adc_val << 9) - 0xFF00  # Exact RTL: {1'b0,adc,9'b0} - {1'b0,8'hFF,9'b0}/2
        adc_signed = saturate(adc_signed, 18)
        
        # NCO lookup (ignoring dithering for golden reference)
@@ -430,7 +430,13 @@ end
 // DUT INSTANTIATION
 // ============================================================================

-radar_system_top dut (
+radar_system_top #(
+`ifdef USB_MODE_1
+    .USB_MODE(1)  // FT2232H interface (production 50T board)
+`else
+    .USB_MODE(0)  // FT601 interface (200T dev board)
+`endif
+) dut (
    // System Clocks
    .clk_100m(clk_100m),
    .clk_120m_dac(clk_120m_dac),
@@ -619,7 +625,11 @@ initial begin
    // Optional: dump specific signals for debugging
    $dumpvars(1, dut.tx_inst);
    $dumpvars(1, dut.rx_inst);
+    `ifdef USB_MODE_1
+    $dumpvars(1, dut.gen_ft2232h.usb_inst);
+    `else
    $dumpvars(1, dut.gen_ft601.usb_inst);
+    `endif
 end

 endmodule
@@ -382,7 +382,13 @@ end
 // ============================================================================
 // DUT INSTANTIATION
 // ============================================================================
-radar_system_top dut (
+radar_system_top #(
+`ifdef USB_MODE_1
+    .USB_MODE(1)  // FT2232H interface (production 50T board)
+`else
+    .USB_MODE(0)  // FT601 interface (200T dev board)
+`endif
+) dut (
    .clk_100m(clk_100m),
    .clk_120m_dac(clk_120m_dac),
    .ft601_clk_in(ft601_clk_in),
@@ -554,10 +560,10 @@ initial begin
    do_reset;

    // CRITICAL: Configure stream control to range-only BEFORE any chirps
-    // fire. The USB write FSM blocks on doppler_valid_ft if doppler stream
-    // is enabled but no Doppler data arrives (needs 32 chirps/frame).
-    // Without this, the write FSM deadlocks and the read FSM can never
-    // activate (it requires write FSM == IDLE).
+    // fire. The USB write FSM gates on pending flags: if doppler stream is
+    // enabled but no Doppler data arrives (needs 32 chirps/frame), the FSM
+    // stays in IDLE waiting for doppler_data_pending. With the write FSM
+    // not in IDLE, the read FSM cannot activate (bus arbitration rule).
    bfm_send_cmd(8'h04, 8'h00, 16'h0001);  // stream_control = range only
    // Wait for stream_control CDC to propagate (2-stage sync in ft601_clk)
    // Must be long enough that stream_ctrl_sync_1 is updated before any
@@ -778,7 +784,7 @@ initial begin

    // Restore defaults for subsequent tests
    bfm_send_cmd(8'h01, 8'h00, 16'h0001);  // mode = auto-scan
-    bfm_send_cmd(8'h04, 8'h00, 16'h0001);  // keep range-only (prevents write FSM deadlock)
+    bfm_send_cmd(8'h04, 8'h00, 16'h0001);  // keep range-only (TB lacks 32-chirp doppler data)
    bfm_send_cmd(8'h10, 8'h00, 16'd3000);  // restore long chirp cycles

    $display("");
@@ -913,7 +919,7 @@ initial begin
    // Need to re-send configuration since reset clears all registers
    stm32_mixers_enable = 1;
    ft601_txe = 0;
-    bfm_send_cmd(8'h04, 8'h00, 16'h0001);  // stream_control = range only (prevent deadlock)
+    bfm_send_cmd(8'h04, 8'h00, 16'h0001);  // stream_control = range only (TB lacks doppler data)
    #500;  // Wait for stream_control CDC
    bfm_send_cmd(8'h01, 8'h00, 16'h0001);  // auto-scan
    bfm_send_cmd(8'h10, 8'h00, 16'd100);   // short timing
@@ -947,7 +953,7 @@ initial begin
    check(dut.host_stream_control == 3'b000,
          "G10.2: All streams disabled (stream_control = 3'b000)");

-    // G10.3: Re-enable range only (keep range-only to prevent write FSM deadlock)
+    // G10.3: Re-enable range only (TB uses range-only — no doppler processing)
    bfm_send_cmd(8'h04, 8'h00, 16'h0001);  // stream_control = 3'b001
    check(dut.host_stream_control == 3'b001,
          "G10.3: Range stream re-enabled (stream_control = 3'b001)");
@@ -6,15 +6,11 @@ module tb_usb_data_interface;
    localparam CLK_PERIOD     = 10.0;  // 100 MHz main clock
    localparam FT_CLK_PERIOD  = 10.0;  // 100 MHz FT601 clock (asynchronous)

-    // State definitions (mirror the DUT)
-    localparam [2:0] S_IDLE           = 3'd0,
-                     S_SEND_HEADER    = 3'd1,
-                     S_SEND_RANGE     = 3'd2,
-                     S_SEND_DOPPLER   = 3'd3,
-                     S_SEND_DETECT    = 3'd4,
-                     S_SEND_FOOTER    = 3'd5,
-                     S_WAIT_ACK       = 3'd6,
-                     S_SEND_STATUS    = 3'd7;  // Gap 2: status readback
+    // State definitions (mirror the DUT — 4-state packed-word FSM)
+    localparam [3:0] S_IDLE           = 4'd0,
+                     S_SEND_DATA_WORD = 4'd1,
+                     S_SEND_STATUS    = 4'd2,
+                     S_WAIT_ACK       = 4'd3;

    // ── Signals ────────────────────────────────────────────────
    reg         clk;
@@ -219,9 +215,9 @@ module tb_usb_data_interface;
        end
    endtask

-    // ── Helper: wait for DUT to reach a specific state ─────────
+    // ── Helper: wait for DUT to reach a specific write FSM state ──
    task wait_for_state;
-        input [2:0] target;
+        input [3:0] target;
        input integer max_cyc;
        integer cnt;
        begin
@@ -280,7 +276,7 @@ module tb_usb_data_interface;
    // Set data_pending flags directly via hierarchical access.
    // This is the standard TB technique for internal state setup —
    // bypasses the CDC path for immediate, reliable flag setting.
-    // Call BEFORE assert_range_valid in tests that need SEND_DOPPLER/DETECT.
+    // Call BEFORE assert_range_valid in tests that need doppler/cfar data.
    task preload_pending_data;
        begin
            @(posedge ft601_clk_in);
@@ -354,24 +350,26 @@ module tb_usb_data_interface;
        end
    endtask

-    // Drive a complete packet through the FSM by sequentially providing
-    // range, doppler (4x), and cfar valid pulses.
+    // Drive a complete data packet through the new 3-word packed FSM.
+    // Pre-loads pending flags, triggers range_valid, and waits for IDLE.
+    // With the new FSM, all data is pre-packed in IDLE then sent as 3 words.
    task drive_full_packet;
        input [31:0] rng;
        input [15:0] dr;
        input [15:0] di;
        input        det;
        begin
-            // Pre-load pending flags so FSM enters doppler/cfar states
+            // Set doppler/cfar captured values via CDC inputs
+            @(posedge clk);
+            doppler_real   = dr;
+            doppler_imag   = di;
+            cfar_detection = det;
+            @(posedge clk);
+            // Pre-load pending flags so FSM includes doppler/cfar in packet
            preload_pending_data;
+            // Trigger the packet
            assert_range_valid(rng);
-            wait_for_state(S_SEND_DOPPLER, 100);
-            pulse_doppler_once(dr, di);
-            pulse_doppler_once(dr, di);
-            pulse_doppler_once(dr, di);
-            pulse_doppler_once(dr, di);
-            wait_for_state(S_SEND_DETECT, 100);
-            pulse_cfar_once(det);
+            // Wait for complete packet cycle: IDLE → SEND_DATA_WORD(×3) → WAIT_ACK → IDLE
            wait_for_state(S_IDLE, 100);
        end
    endtask
@@ -414,101 +412,138 @@ module tb_usb_data_interface;
              "ft601_siwu_n=1 after reset");

        // ════════════════════════════════════════════════════════
-        // TEST GROUP 2: Range data packet
+        // TEST GROUP 2: Data packet word packing
        //
-        // Use backpressure to freeze the FSM at specific states
-        // so we can reliably sample outputs.
+        // New FSM packs 11-byte data into 3 × 32-bit words:
+        //   Word 0: {HEADER, range[31:24], range[23:16], range[15:8]}
+        //   Word 1: {range[7:0], dop_re_hi, dop_re_lo, dop_im_hi}
+        //   Word 2: {dop_im_lo, detection, FOOTER, 0x00}  BE=1110
+        //
+        // The DUT uses range_data_ready (1-cycle delayed range_valid_ft)
+        // to trigger packing.  Doppler/CFAR _cap registers must be
+        // pre-loaded via hierarchical access because no valid pulse is
+        // given in this test (we only want to verify packing, not CDC).
        // ════════════════════════════════════════════════════════
-        $display("\n--- Test Group 2: Range Data Packet ---");
+        $display("\n--- Test Group 2: Data Packet Word Packing ---");
        apply_reset;
+        ft601_txe = 1;  // Stall so we can inspect packed words

-        // Stall at SEND_HEADER so we can verify first range word later
-        ft601_txe = 1;
+        // Set known doppler/cfar values on clk-domain inputs
+        @(posedge clk);
+        doppler_real   = 16'hABCD;
+        doppler_imag   = 16'hEF01;
+        cfar_detection = 1'b1;
+        @(posedge clk);
+
+        // Pre-load pending flags AND captured-data registers directly.
+        // No doppler/cfar valid pulses are given, so the CDC capture path
+        // never fires — we must set the _cap registers via hierarchical
+        // access for the word-packing checks to be meaningful.
        preload_pending_data;
+        @(posedge ft601_clk_in);
+        uut.doppler_real_cap   = 16'hABCD;
+        uut.doppler_imag_cap   = 16'hEF01;
+        uut.cfar_detection_cap = 1'b1;
+        @(posedge ft601_clk_in);
+
        assert_range_valid(32'hDEAD_BEEF);
-        wait_for_state(S_SEND_HEADER, 50);
-        repeat (2) @(posedge ft601_clk_in); #1;
-        check(uut.current_state === S_SEND_HEADER,
-              "Stalled in SEND_HEADER (backpressure)");

-        // Release: FSM drives header then moves to SEND_RANGE_DATA
+        // FSM should be in SEND_DATA_WORD, stalled on ft601_txe=1
+        wait_for_state(S_SEND_DATA_WORD, 50);
+        repeat (2) @(posedge ft601_clk_in); #1;
+
+        check(uut.current_state === S_SEND_DATA_WORD,
+              "Stalled in SEND_DATA_WORD (backpressure)");
+
+        // Verify pre-packed words
+        // range_profile = 0xDEAD_BEEF → range[31:24]=0xDE, [23:16]=0xAD, [15:8]=0xBE, [7:0]=0xEF
+        // Word 0: {0xAA, 0xDE, 0xAD, 0xBE}
+        check(uut.data_pkt_word0 === {8'hAA, 8'hDE, 8'hAD, 8'hBE},
+              "Word 0: {HEADER=AA, range[31:8]}");
+        // Word 1: {0xEF, 0xAB, 0xCD, 0xEF}
+        check(uut.data_pkt_word1 === {8'hEF, 8'hAB, 8'hCD, 8'hEF},
+              "Word 1: {range[7:0], dop_re, dop_im_hi}");
+        // Word 2: {0x01, detection_byte, 0x55, 0x00}
+        // detection_byte bit 7 = frame_start (sample_counter==0 → 1), bit 0 = cfar=1
+        // so detection_byte = 8'b1000_0001 = 8'h81
+        check(uut.data_pkt_word2 === {8'h01, 8'h81, 8'h55, 8'h00},
+              "Word 2: {dop_im_lo, det=81, FOOTER=55, pad=00}");
+        check(uut.data_pkt_be2 === 4'b1110,
+              "Word 2 BE=1110 (3 valid bytes + 1 pad)");
+
+        // Release backpressure and verify word 0 appears on bus.
+        // On the first posedge with !ft601_txe the FSM drives word 0 and
+        // advances data_word_idx 0→1 via NBA.  After #1 the NBA has
+        // resolved, so we see idx=1 and ft601_data_out=word0.
        ft601_txe = 0;
        @(posedge ft601_clk_in); #1;
-        // Now the FSM registered the header output and will transition
-        // At the NEXT posedge the state becomes SEND_RANGE_DATA
-        @(posedge ft601_clk_in); #1;
-
-        check(uut.current_state === S_SEND_RANGE,
-              "Entered SEND_RANGE_DATA after header");
-
-        // The first range word should be on the data bus (byte_counter=0 just
-        // drove range_profile_cap, byte_counter incremented to 1)
-        check(uut.ft601_data_out === 32'hDEAD_BEEF || uut.byte_counter <= 8'd1,
-              "Range data word 0 driven (range_profile_cap)");

+        check(uut.ft601_data_out === {8'hAA, 8'hDE, 8'hAD, 8'hBE},
+              "Word 0 driven on data bus after backpressure release");
        check(ft601_wr_n === 1'b0,
-              "Write strobe active during range data");
-
+              "Write strobe active during SEND_DATA_WORD");
        check(ft601_be === 4'b1111,
-              "Byte enable=1111 for range data");
+              "Byte enable=1111 for word 0");
+        check(uut.ft601_data_oe === 1'b1,
+              "Data bus output enabled during SEND_DATA_WORD");

-        // Wait for all 4 range words to complete
-        wait_for_state(S_SEND_DOPPLER, 50);
-        #1;
-        check(uut.current_state === S_SEND_DOPPLER,
-              "Advanced to SEND_DOPPLER_DATA after 4 range words");
+        // Next posedge: FSM drives word 1, advances idx 1→2.
+        // After NBA: idx=2, ft601_data_out=word1.
+        @(posedge ft601_clk_in); #1;
+        check(uut.data_word_idx === 2'd2,
+              "data_word_idx advanced past word 1 (now 2)");
+        check(uut.ft601_data_out === {8'hEF, 8'hAB, 8'hCD, 8'hEF},
+              "Word 1 driven on data bus");
+        check(ft601_be === 4'b1111,
+              "Byte enable=1111 for word 1");
+
+        // Next posedge: FSM drives word 2, idx resets 2→0,
+        // and current_state transitions to WAIT_ACK.
+        @(posedge ft601_clk_in); #1;
+        check(uut.current_state === S_WAIT_ACK,
+              "Transitioned to WAIT_ACK after 3 data words");
+        check(uut.ft601_data_out === {8'h01, 8'h81, 8'h55, 8'h00},
+              "Word 2 driven on data bus");
+        check(ft601_be === 4'b1110,
+              "Byte enable=1110 for word 2 (last byte is pad)");
+
+        // Then back to IDLE
+        @(posedge ft601_clk_in); #1;
+        check(uut.current_state === S_IDLE,
+              "Returned to IDLE after WAIT_ACK");

        // ════════════════════════════════════════════════════════
-        // TEST GROUP 3: Header verification (stall to observe)
+        // TEST GROUP 3: Header and footer verification
        // ════════════════════════════════════════════════════════
-        $display("\n--- Test Group 3: Header Verification ---");
+        $display("\n--- Test Group 3: Header and Footer Verification ---");
        apply_reset;
-        ft601_txe = 1;  // Stall at SEND_HEADER
+        ft601_txe = 1;  // Stall to inspect

        @(posedge clk);
-        range_profile = 32'hCAFE_BABE;
-        range_valid   = 1;
-        repeat (4) @(posedge ft601_clk_in);
+        doppler_real   = 16'h0000;
+        doppler_imag   = 16'h0000;
+        cfar_detection = 1'b0;
        @(posedge clk);
-        range_valid = 0;
-        repeat (3) @(posedge ft601_clk_in);
+        preload_pending_data;
+        assert_range_valid(32'hCAFE_BABE);

-        wait_for_state(S_SEND_HEADER, 50);
+        wait_for_state(S_SEND_DATA_WORD, 50);
        repeat (2) @(posedge ft601_clk_in); #1;

-        check(uut.current_state === S_SEND_HEADER,
-              "Stalled in SEND_HEADER with backpressure");
-
-        // Release backpressure - header will be latched at next posedge
-        ft601_txe = 0;
-        @(posedge ft601_clk_in); #1;
-
-        check(uut.ft601_data_out[7:0] === 8'hAA,
-              "Header byte 0xAA on data bus");
-        check(ft601_be === 4'b0001,
-              "Byte enable=0001 for header (lower byte only)");
-        check(ft601_wr_n === 1'b0,
-              "Write strobe active during header");
-        check(uut.ft601_data_oe === 1'b1,
-              "Data bus output enabled during header");
+        // Header is in byte 3 (MSB) of word 0
+        check(uut.data_pkt_word0[31:24] === 8'hAA,
+              "Header byte 0xAA in word 0 MSB");
+        // Footer is in byte 1 (bits [15:8]) of word 2
+        check(uut.data_pkt_word2[15:8] === 8'h55,
+              "Footer byte 0x55 in word 2");

        // ════════════════════════════════════════════════════════
-        // TEST GROUP 4: Doppler data verification
+        // TEST GROUP 4: Doppler data capture verification
        // ════════════════════════════════════════════════════════
-        $display("\n--- Test Group 4: Doppler Data Verification ---");
+        $display("\n--- Test Group 4: Doppler Data Capture ---");
        apply_reset;
        ft601_txe = 0;

-        // Preload only doppler pending (not cfar) so the FSM sends
-        // doppler data. After doppler, SEND_DETECT sees cfar_data_pending=0
-        // and skips to SEND_FOOTER, then WAIT_ACK, then IDLE.
-        preload_doppler_pending;
-        assert_range_valid(32'h0000_0001);
-        wait_for_state(S_SEND_DOPPLER, 100);
-        #1;
-        check(uut.current_state === S_SEND_DOPPLER,
-              "Reached SEND_DOPPLER_DATA");
-
        // Provide doppler data via valid pulse (updates captured values)
        @(posedge clk);
        doppler_real  = 16'hAAAA;
@@ -524,110 +559,70 @@ module tb_usb_data_interface;
        check(uut.doppler_imag_cap === 16'h5555,
              "doppler_imag captured correctly");

-        // The FSM has doppler_data_pending set and sends 4 bytes, then
-        // transitions past SEND_DETECT (cfar_data_pending=0) to IDLE.
+        // Drive a packet with pending doppler + cfar (both needed for gating
+        // since all streams are enabled after reset/apply_reset).
+        preload_pending_data;
+        assert_range_valid(32'h0000_0001);
        wait_for_state(S_IDLE, 100);
        #1;
        check(uut.current_state === S_IDLE,
-              "Doppler done, packet completed");
+              "Packet completed with doppler data");
+        check(uut.doppler_data_pending === 1'b0,
+              "doppler_data_pending cleared after packet");

        // ════════════════════════════════════════════════════════
        // TEST GROUP 5: CFAR detection data
        // ════════════════════════════════════════════════════════
        $display("\n--- Test Group 5: CFAR Detection Data ---");
-        // Start a new packet with both doppler and cfar pending to verify
-        // cfar data is properly sent in SEND_DETECTION_DATA.
        apply_reset;
        ft601_txe = 0;
        preload_pending_data;
        assert_range_valid(32'h0000_0002);
-        // FSM races through: HEADER -> RANGE -> DOPPLER -> DETECT -> FOOTER -> IDLE
-        // All pending flags consumed proves SEND_DETECT was entered.
        wait_for_state(S_IDLE, 200);
        #1;
        check(uut.cfar_data_pending === 1'b0,
-              "Starting in SEND_DETECTION_DATA");
-
-        // Verify the full packet completed with cfar data consumed
+              "cfar_data_pending cleared after packet");
        check(uut.current_state === S_IDLE &&
              uut.doppler_data_pending === 1'b0 &&
              uut.cfar_data_pending === 1'b0,
-              "CFAR detection sent, FSM advanced past SEND_DETECTION_DATA");
+              "CFAR detection sent, all pending flags cleared");

        // ════════════════════════════════════════════════════════
-        // TEST GROUP 6: Footer check
-        //
-        // Strategy: drive packet with ft601_txe=0 all the way through.
-        // The SEND_FOOTER state is only active for 1 cycle, but we can
-        // poll the state machine at each ft601_clk_in edge to observe
-        // it. We use a monitor-style approach: run the packet and
-        // capture what ft601_data_out contains when we see SEND_FOOTER.
+        // TEST GROUP 6: Footer retained after packet
        // ════════════════════════════════════════════════════════
-        $display("\n--- Test Group 6: Footer Check ---");
+        $display("\n--- Test Group 6: Footer Retention ---");
        apply_reset;
        ft601_txe = 0;

-        // Drive packet through range data
+        @(posedge clk);
+        cfar_detection = 1'b1;
+        @(posedge clk);
        preload_pending_data;
        assert_range_valid(32'hFACE_FEED);
-        wait_for_state(S_SEND_DOPPLER, 100);
-        // Feed doppler data (need 4 pulses)
-        pulse_doppler_once(16'h1111, 16'h2222);
-        pulse_doppler_once(16'h1111, 16'h2222);
-        pulse_doppler_once(16'h1111, 16'h2222);
-        pulse_doppler_once(16'h1111, 16'h2222);
-        wait_for_state(S_SEND_DETECT, 100);
-        // Feed cfar data, but keep ft601_txe=0 so it flows through
-        pulse_cfar_once(1'b1);
-
-        // Now the FSM should pass through SEND_FOOTER quickly.
-        // Use wait_for_state to reach SEND_FOOTER, or it may already
-        // be at WAIT_ACK/IDLE. Let's catch WAIT_ACK or IDLE.
-        // The footer values are latched into registers, so we can
-        // verify them even after the state transitions.
-        // Key verification: the FOOTER constant (0x55) must have been
-        // driven. We check this by looking at the constant definition.
-        // Since we can't easily freeze the FSM at SEND_FOOTER without
-        // also stalling SEND_DETECTION_DATA (both check ft601_txe),
-        // we verify the footer indirectly:
-        // 1. The packet completed (reached IDLE/WAIT_ACK)
-        // 2. ft601_data_out last held 0x55 during SEND_FOOTER
-
        wait_for_state(S_IDLE, 100);
        #1;
-        // If we reached IDLE, the full sequence ran including footer
        check(uut.current_state === S_IDLE,
              "Full packet incl. footer completed, back in IDLE");

-        // The registered ft601_data_out should still hold 0x55 from
-        // SEND_FOOTER (WAIT_ACK and IDLE don't overwrite ft601_data_out).
-        // Actually, looking at the DUT: WAIT_ACK only sets wr_n=1 and
-        // data_oe=0, it doesn't change ft601_data_out. So it retains 0x55.
-        check(uut.ft601_data_out[7:0] === 8'h55,
-              "ft601_data_out retains footer 0x55 after packet");
+        // The last word driven was word 2 which contains footer 0x55.
+        // WAIT_ACK and IDLE don't overwrite ft601_data_out, so it retains
+        // the last driven value.
+        check(uut.ft601_data_out[15:8] === 8'h55,
+              "ft601_data_out retains footer 0x55 in word 2 position");

-        // Verify WAIT_ACK behavior by doing another packet and catching it
+        // Verify WAIT_ACK → IDLE transition
        apply_reset;
        ft601_txe = 0;
        preload_pending_data;
        assert_range_valid(32'h1234_5678);
-        wait_for_state(S_SEND_DOPPLER, 100);
-        pulse_doppler_once(16'hABCD, 16'hEF01);
-        pulse_doppler_once(16'hABCD, 16'hEF01);
-        pulse_doppler_once(16'hABCD, 16'hEF01);
-        pulse_doppler_once(16'hABCD, 16'hEF01);
-        wait_for_state(S_SEND_DETECT, 100);
-        pulse_cfar_once(1'b0);
-        // WAIT_ACK lasts exactly 1 ft601_clk_in cycle then goes IDLE.
-        // Poll for IDLE (which means WAIT_ACK already happened).
        wait_for_state(S_IDLE, 100);
        #1;
        check(uut.current_state === S_IDLE,
              "Returned to IDLE after WAIT_ACK");
        check(ft601_wr_n === 1'b1,
-              "ft601_wr_n deasserted in IDLE (was deasserted in WAIT_ACK)");
+              "ft601_wr_n deasserted in IDLE");
        check(uut.ft601_data_oe === 1'b0,
-              "Data bus released in IDLE (was released in WAIT_ACK)");
+              "Data bus released in IDLE");

        // ════════════════════════════════════════════════════════
        // TEST GROUP 7: Full packet sequence (end-to-end)
@@ -646,23 +641,24 @@ module tb_usb_data_interface;
        // ════════════════════════════════════════════════════════
        $display("\n--- Test Group 8: FIFO Backpressure ---");
        apply_reset;
-        ft601_txe = 1;
+        ft601_txe = 1;  // FIFO full — stall

+        preload_pending_data;
        assert_range_valid(32'hBBBB_CCCC);

-        wait_for_state(S_SEND_HEADER, 50);
+        wait_for_state(S_SEND_DATA_WORD, 50);
        repeat (10) @(posedge ft601_clk_in); #1;

-        check(uut.current_state === S_SEND_HEADER,
-              "Stalled in SEND_HEADER when ft601_txe=1 (FIFO full)");
+        check(uut.current_state === S_SEND_DATA_WORD,
+              "Stalled in SEND_DATA_WORD when ft601_txe=1 (FIFO full)");
        check(ft601_wr_n === 1'b1,
              "ft601_wr_n not asserted during backpressure stall");

        ft601_txe = 0;
-        repeat (2) @(posedge ft601_clk_in); #1;
+        repeat (6) @(posedge ft601_clk_in); #1;

-        check(uut.current_state !== S_SEND_HEADER,
-              "Resumed from SEND_HEADER after backpressure released");
+        check(uut.current_state === S_IDLE || uut.current_state === S_WAIT_ACK,
+              "Resumed and completed after backpressure released");

        // ════════════════════════════════════════════════════════
        // TEST GROUP 9: Clock divider
@@ -705,13 +701,6 @@ module tb_usb_data_interface;
        ft601_txe = 0;
        preload_pending_data;
        assert_range_valid(32'h1111_2222);
-        wait_for_state(S_SEND_DOPPLER, 100);
-        pulse_doppler_once(16'h3333, 16'h4444);
-        pulse_doppler_once(16'h3333, 16'h4444);
-        pulse_doppler_once(16'h3333, 16'h4444);
-        pulse_doppler_once(16'h3333, 16'h4444);
-        wait_for_state(S_SEND_DETECT, 100);
-        pulse_cfar_once(1'b0);
        wait_for_state(S_WAIT_ACK, 50);
        #1;

@@ -805,7 +794,7 @@ module tb_usb_data_interface;
        // Start a write packet
        preload_pending_data;
        assert_range_valid(32'hFACE_FEED);
-        wait_for_state(S_SEND_HEADER, 50);
+        wait_for_state(S_SEND_DATA_WORD, 50);
        @(posedge ft601_clk_in); #1;

        // While write FSM is active, assert RXF=0 (host has data)
@@ -818,13 +807,6 @@ module tb_usb_data_interface;

        // Deassert RXF, complete the write packet
        ft601_rxf = 1;
-        wait_for_state(S_SEND_DOPPLER, 100);
-        pulse_doppler_once(16'hAAAA, 16'hBBBB);
-        pulse_doppler_once(16'hAAAA, 16'hBBBB);
-        pulse_doppler_once(16'hAAAA, 16'hBBBB);
-        pulse_doppler_once(16'hAAAA, 16'hBBBB);
-        wait_for_state(S_SEND_DETECT, 100);
-        pulse_cfar_once(1'b1);
        wait_for_state(S_IDLE, 100);
        @(posedge ft601_clk_in); #1;

@@ -841,32 +823,42 @@ module tb_usb_data_interface;
        // ════════════════════════════════════════════════════════
        // TEST GROUP 15: Stream Control Gating (Gap 2)
        // Verify that disabling individual streams causes the write
-        // FSM to skip those data phases.
+        // FSM to zero those fields in the packed words.
        // ════════════════════════════════════════════════════════
        $display("\n--- Test Group 15: Stream Control Gating (Gap 2) ---");

        // 15a: Disable doppler stream (stream_control = 3'b101 = range + cfar only)
        apply_reset;
-        ft601_txe = 0;
+        ft601_txe = 1;  // Stall to inspect packed words
        stream_control = 3'b101;  // range + cfar, no doppler
        // Wait for CDC propagation (2-stage sync)
        repeat (6) @(posedge ft601_clk_in);

-        // Preload cfar pending so the FSM enters the SEND_DETECT data path
-        // (without it, SEND_DETECT skips immediately on !cfar_data_pending).
-        preload_cfar_pending;
-        // Drive range valid — triggers write FSM
-        assert_range_valid(32'hAA11_BB22);
-        // FSM: IDLE -> SEND_HEADER -> SEND_RANGE (doppler disabled) -> SEND_DETECT -> FOOTER
-        // The FSM races through SEND_DETECT in 1 cycle (cfar_data_pending is consumed).
-        // Verify the packet completed correctly (doppler was skipped).
-        wait_for_state(S_IDLE, 200);
-        #1;
-        // Reaching IDLE proves: HEADER -> RANGE -> (skip DOPPLER) -> DETECT -> FOOTER -> ACK -> IDLE.
-        // cfar_data_pending consumed confirms SEND_DETECT was entered.
-        check(uut.current_state === S_IDLE && uut.cfar_data_pending === 1'b0,
-              "Stream gate: reached SEND_DETECT (range sent, doppler skipped)");
+        @(posedge clk);
+        doppler_real   = 16'hAAAA;
+        doppler_imag   = 16'hBBBB;
+        cfar_detection = 1'b1;
+        @(posedge clk);

+        preload_cfar_pending;
+        assert_range_valid(32'hAA11_BB22);
+
+        wait_for_state(S_SEND_DATA_WORD, 200);
+        repeat (2) @(posedge ft601_clk_in); #1;
+
+        // With doppler disabled, doppler fields in words 1 and 2 should be zero
+        // Word 1: {range[7:0], 0x00, 0x00, 0x00} (doppler zeroed)
+        check(uut.data_pkt_word1[23:0] === 24'h000000,
+              "Stream gate: doppler bytes zeroed in word 1 when disabled");
+
+        // Word 2 byte 3 (dop_im_lo) should also be zero
+        check(uut.data_pkt_word2[31:24] === 8'h00,
+              "Stream gate: dop_im_lo zeroed in word 2 when disabled");
+
+        // Let it complete
+        ft601_txe = 0;
+        wait_for_state(S_IDLE, 100);
+        #1;
        check(uut.current_state === S_IDLE,
              "Stream gate: packet completed without doppler");

@@ -951,28 +943,6 @@ module tb_usb_data_interface;
              "Status readback: returned to IDLE after 8-word response");

        // Verify the status snapshot was captured correctly.
-        // status_words[0] = {0xFF, 3'b000, mode[1:0], 5'b0, stream_ctrl[2:0], cfar_threshold[15:0]}
-        // = {8'hFF, 3'b000, 2'b01, 5'b00000, 3'b101, 16'hABCD}
-        // = 0xFF_09_05_ABCD... let's compute:
-        // Byte 3: 0xFF = 8'hFF
-        // Byte 2: {3'b000, 2'b01} = 5'b00001 + 3 high bits of next field...
-        // Actually the packing is: {8'hFF, 3'b000, status_radar_mode[1:0], 5'b00000, status_stream_ctrl[2:0], status_cfar_threshold[15:0]}
-        // = {8'hFF, 3'b000, 2'b01, 5'b00000, 3'b101, 16'hABCD}
-        // = 8'hFF, 5'b00001, 8'b00000101, 16'hABCD
-        // = FF_09_05_ABCD? Let me compute carefully:
-        // Bits [31:24] = 8'hFF = 0xFF
-        // Bits [23:21] = 3'b000
-        // Bits [20:19] = 2'b01 (mode)
-        // Bits [18:14] = 5'b00000
-        // Bits [13:11] = 3'b101 (stream_ctrl)
-        // Bits [10:0]  = ... wait, cfar_threshold is 16 bits → [15:0]
-        // Total bits = 8+3+2+5+3+16 = 37 bits — won't fit in 32!
-        // Re-reading the RTL: the packing at line 241 is:
-        //   {8'hFF, 3'b000, status_radar_mode, 5'b00000, status_stream_ctrl, status_cfar_threshold}
-        //   = 8 + 3 + 2 + 5 + 3 + 16 = 37 bits
-        // This would be truncated to 32 bits. Let me re-read the actual RTL to check.
-        // For now, just verify status_words[1] (word index 1 in the packet = idx 2 in FSM)
-        // status_words[1] = {status_long_chirp, status_long_listen} = {16'd3000, 16'd13700}
        check(uut.status_words[1] === {16'd3000, 16'd13700},
              "Status readback: word 1 = {long_chirp, long_listen}");
        check(uut.status_words[2] === {16'd17540, 16'd50},
@@ -1,3 +1,17 @@
+/**
+ * usb_data_interface.v
+ *
+ * FT601 USB 3.0 SuperSpeed FIFO Interface (32-bit bus, 100 MHz ft601_clk).
+ * Used on the 200T premium dev board. Production 50T board uses
+ * usb_data_interface_ft2232h.v (FT2232H, 8-bit, 60 MHz) instead.
+ *
+ * USB disconnect recovery:
+ *   A clock-activity watchdog in the clk domain detects when ft601_clk_in
+ *   stops (USB cable unplugged). After ~0.65 ms of silence (65536 system
+ *   clocks) it asserts ft601_clk_lost, which is OR'd into the FT-domain
+ *   reset so FSMs and FIFOs return to a clean state. When ft601_clk_in
+ *   resumes, a 2-stage reset synchronizer deasserts the reset cleanly.
+ */
 module usb_data_interface (
    input wire clk,              // Main clock (100MHz recommended)
    input wire reset_n,
@@ -15,13 +29,18 @@ module usb_data_interface (
    // FT601 Interface (Slave FIFO mode)
    // Data bus
    inout wire [31:0] ft601_data,    // 32-bit bidirectional data bus
-    output reg [3:0] ft601_be,       // Byte enable (4 lanes for 32-bit mode)
+    output reg [3:0] ft601_be,       // Byte enable (active-HIGH per DS_FT600Q-FT601Q Table 3.2)
    
    // Control signals
-    output reg ft601_txe_n,          // Transmit enable (active low)
-    output reg ft601_rxf_n,          // Receive enable (active low)
-    input wire ft601_txe,             // TXE: Transmit FIFO Not Full (high = space available to write)
-    input wire ft601_rxf,             // RXF: Receive FIFO Not Empty (high = data available to read)
+    // VESTIGIAL OUTPUTS — kept for 200T board port compatibility.
+    // On the 200T, these are constrained to physical pins G21 (TXE) and
+    // G22 (RXF) in xc7a200t_fbg484.xdc. Removing them from the RTL would
+    // break the 200T build. They are reset to 1 and never driven; the
+    // actual FT601 flow-control inputs are ft601_txe and ft601_rxf below.
+    output reg ft601_txe_n,          // VESTIGIAL: unused output, always 1
+    output reg ft601_rxf_n,          // VESTIGIAL: unused output, always 1
+    input wire ft601_txe,             // TXE: Transmit FIFO Not Full (active-low: 0 = space available)
+    input wire ft601_rxf,             // RXF: Receive FIFO Not Empty (active-low: 0 = data available)
    output reg ft601_wr_n,            // Write strobe (active low)
    output reg ft601_rd_n,            // Read strobe (active low)
    output reg ft601_oe_n,            // Output enable (active low)
@@ -97,21 +116,26 @@ localparam FT601_BURST_SIZE = 512;    // Max burst size in bytes
 // ============================================================================
 // WRITE FSM State definitions (Verilog-2001 compatible)
 // ============================================================================
-localparam [2:0] IDLE                = 3'd0,
-                 SEND_HEADER         = 3'd1,
-                 SEND_RANGE_DATA     = 3'd2,
-                 SEND_DOPPLER_DATA   = 3'd3,
-                 SEND_DETECTION_DATA = 3'd4,
-                 SEND_FOOTER         = 3'd5,
-                 WAIT_ACK            = 3'd6,
-                 SEND_STATUS         = 3'd7;  // Gap 2: status readback
+// Rewritten: data packet is now 3 x 32-bit writes (11 payload bytes + 1 pad).
+// Word 0: {HEADER, range[31:24], range[23:16], range[15:8]}  BE=1111
+// Word 1: {range[7:0], doppler_real[15:8], doppler_real[7:0], doppler_imag[15:8]} BE=1111
+// Word 2: {doppler_imag[7:0], detection, FOOTER, 8'h00}      BE=1110
+localparam [3:0] IDLE                = 4'd0,
+                 SEND_DATA_WORD      = 4'd1,
+                 SEND_STATUS         = 4'd2,
+                 WAIT_ACK            = 4'd3;

-reg [2:0] current_state;
-reg [7:0] byte_counter;
-reg [31:0] data_buffer;
+reg [3:0] current_state;
+reg [1:0] data_word_idx;     // 0..2 for 3-word data packet
 reg [31:0] ft601_data_out;
 reg ft601_data_oe;  // Output enable for bidirectional data bus

+// Pre-packed data words (registered snapshot of CDC'd data)
+reg [31:0] data_pkt_word0;
+reg [31:0] data_pkt_word1;
+reg [31:0] data_pkt_word2;
+reg [3:0]  data_pkt_be2;     // BE for last word (BE=1110 since byte 3 is pad)
+
 // ============================================================================
 // READ FSM State definitions (Gap 4: USB Read Path)
 // ============================================================================
@@ -184,6 +208,67 @@ always @(posedge clk or negedge reset_n) begin
    end
 end

+// ============================================================================
+// CLOCK-ACTIVITY WATCHDOG (clk domain)
+// ============================================================================
+// Detects when ft601_clk_in stops (USB cable unplugged). A toggle register
+// in the ft601_clk domain flips every edge. The clk domain synchronizes it
+// and checks for transitions. If no transition is seen for 2^16 = 65536
+// clk cycles (~0.65 ms at 100 MHz), ft601_clk_lost asserts.
+
+// Toggle register: flips every ft601_clk edge (ft601_clk domain)
+reg ft601_heartbeat;
+always @(posedge ft601_clk_in or negedge ft601_reset_n) begin
+    if (!ft601_reset_n)
+        ft601_heartbeat <= 1'b0;
+    else
+        ft601_heartbeat <= ~ft601_heartbeat;
+end
+
+// Synchronize heartbeat into clk domain (2-stage)
+(* ASYNC_REG = "TRUE" *) reg [1:0] ft601_hb_sync;
+reg ft601_hb_prev;
+reg [15:0] ft601_clk_timeout;
+reg ft601_clk_lost;
+
+always @(posedge clk or negedge reset_n) begin
+    if (!reset_n) begin
+        ft601_hb_sync    <= 2'b00;
+        ft601_hb_prev    <= 1'b0;
+        ft601_clk_timeout <= 16'd0;
+        ft601_clk_lost   <= 1'b0;
+    end else begin
+        ft601_hb_sync <= {ft601_hb_sync[0], ft601_heartbeat};
+        ft601_hb_prev <= ft601_hb_sync[1];
+
+        if (ft601_hb_sync[1] != ft601_hb_prev) begin
+            // ft601_clk is alive — reset counter, clear lost flag
+            ft601_clk_timeout <= 16'd0;
+            ft601_clk_lost    <= 1'b0;
+        end else if (!ft601_clk_lost) begin
+            if (ft601_clk_timeout == 16'hFFFF)
+                ft601_clk_lost <= 1'b1;
+            else
+                ft601_clk_timeout <= ft601_clk_timeout + 16'd1;
+        end
+    end
+end
+
+// Effective FT601-domain reset: asserted by global reset OR clock loss.
+// Deassertion synchronized to ft601_clk via 2-stage sync to avoid
+// metastability on the recovery edge.
+(* ASYNC_REG = "TRUE" *) reg [1:0] ft601_reset_sync;
+wire ft601_reset_raw_n = ft601_reset_n & ~ft601_clk_lost;
+
+always @(posedge ft601_clk_in or negedge ft601_reset_raw_n) begin
+    if (!ft601_reset_raw_n)
+        ft601_reset_sync <= 2'b00;
+    else
+        ft601_reset_sync <= {ft601_reset_sync[0], 1'b1};
+end
+
+wire ft601_effective_reset_n = ft601_reset_sync[1];
+
 // FT601-domain captured data (sampled from holding regs on sync'd edge)
 reg [31:0] range_profile_cap;
 reg [15:0] doppler_real_cap;
@@ -197,6 +282,18 @@ reg cfar_detection_cap;
 reg doppler_data_pending;
 reg cfar_data_pending;

+// 1-cycle delayed range trigger.  range_valid_ft fires on the same clock
+// edge that range_profile_cap is captured (non-blocking).  If the FSM
+// reads range_profile_cap on that same edge it sees the STALE value.
+// Delaying the trigger by one cycle guarantees the capture register has
+// settled before the FSM packs the data words.
+reg range_data_ready;
+
+// Frame sync: sample counter (ft601_clk domain, wraps at NUM_CELLS)
+// Bit 7 of detection byte is set when sample_counter == 0 (frame start).
+localparam [11:0] NUM_CELLS = 12'd2048;  // 64 range x 32 doppler
+reg [11:0] sample_counter;
+
 // Gap 2: CDC for stream_control (clk_100m -> ft601_clk_in)
 // stream_control changes infrequently (only on host USB command), so
 // per-bit 2-stage synchronizers are sufficient. No Gray coding needed
@@ -228,8 +325,8 @@ wire range_valid_ft;
 wire doppler_valid_ft;
 wire cfar_valid_ft;

-always @(posedge ft601_clk_in or negedge ft601_reset_n) begin
-    if (!ft601_reset_n) begin
+always @(posedge ft601_clk_in or negedge ft601_effective_reset_n) begin
+    if (!ft601_effective_reset_n) begin
        range_valid_sync   <= 2'b00;
        doppler_valid_sync <= 2'b00;
        cfar_valid_sync    <= 2'b00;
@@ -240,6 +337,7 @@ always @(posedge ft601_clk_in or negedge ft601_reset_n) begin
        doppler_real_cap   <= 16'd0;
        doppler_imag_cap   <= 16'd0;
        cfar_detection_cap <= 1'b0;
+        range_data_ready   <= 1'b0;
        // Fix #5: Default to range-only on reset (prevents write FSM deadlock)
        stream_ctrl_sync_0 <= 3'b001;
        stream_ctrl_sync_1 <= 3'b001;
@@ -276,7 +374,7 @@ always @(posedge ft601_clk_in or negedge ft601_reset_n) begin
            // Word 4: AGC metrics + range_mode
            status_words[4] <= {status_agc_current_gain,        // [31:28]
                                status_agc_peak_magnitude,      // [27:20]
-                                status_agc_saturation_count,    // [19:12]
+                                status_agc_saturation_count,    // [19:12] 8-bit saturation count
                                status_agc_enable,              // [11]
                                9'd0,                           // [10:2] reserved
                                status_range_mode};             // [1:0]
@@ -302,6 +400,10 @@ always @(posedge ft601_clk_in or negedge ft601_reset_n) begin
        if (cfar_valid_sync[1] && !cfar_valid_sync_d) begin
            cfar_detection_cap <= cfar_detection_hold;
        end
+
+        // 1-cycle delayed trigger: ensures range_profile_cap has settled
+        // before the FSM reads it for word packing.
+        range_data_ready <= range_valid_ft;
    end
 end

@@ -314,11 +416,11 @@ assign cfar_valid_ft    = cfar_valid_sync[1]     && !cfar_valid_sync_d;
 // FT601 data bus direction control
 assign ft601_data = ft601_data_oe ? ft601_data_out : 32'hzzzz_zzzz;

-always @(posedge ft601_clk_in or negedge ft601_reset_n) begin
-    if (!ft601_reset_n) begin
+always @(posedge ft601_clk_in or negedge ft601_effective_reset_n) begin
+    if (!ft601_effective_reset_n) begin
        current_state <= IDLE;
        read_state <= RD_IDLE;
-        byte_counter <= 0;
+        data_word_idx <= 2'd0;
        ft601_data_out <= 0;
        ft601_data_oe <= 0;
        ft601_be <= 4'b1111;  // All bytes enabled for 32-bit mode
@@ -336,6 +438,11 @@ always @(posedge ft601_clk_in or negedge ft601_reset_n) begin
        cmd_value <= 16'd0;
        doppler_data_pending <= 1'b0;
        cfar_data_pending <= 1'b0;
+        data_pkt_word0 <= 32'd0;
+        data_pkt_word1 <= 32'd0;
+        data_pkt_word2 <= 32'd0;
+        data_pkt_be2   <= 4'b1110;
+        sample_counter <= 12'd0;
        // NOTE: ft601_clk_out is driven by the clk-domain always block below.
        // Do NOT assign it here (ft601_clk_in domain) — causes multi-driven net.
    end else begin
@@ -424,122 +531,64 @@ always @(posedge ft601_clk_in or negedge ft601_reset_n) begin
                        current_state <= SEND_STATUS;
                        status_word_idx <= 3'd0;
                    end
-                    // Trigger write FSM on range_valid edge (primary data source).
-                    // Doppler/cfar data_pending flags are checked inside
-                    // SEND_DOPPLER_DATA and SEND_DETECTION_DATA to skip or send.
-                    // Do NOT trigger on pending flags alone — they're sticky and
-                    // would cause repeated packet starts without new range data.
-                    else if (range_valid_ft && stream_range_en) begin
+                    // Trigger on range_data_ready (1 cycle after range_valid_ft)
+                    // so that range_profile_cap has settled from the CDC block.
+                    // Gate on pending flags: only send when all enabled
+                    // streams have fresh data (avoids stale doppler/CFAR)
+                    else if (range_data_ready && stream_range_en
+                             && (!stream_doppler_en || doppler_data_pending)
+                             && (!stream_cfar_en    || cfar_data_pending)) begin
                        // Don't start write if a read is about to begin
                        if (ft601_rxf) begin  // rxf=1 means no host data pending
-                            current_state <= SEND_HEADER;
-                            byte_counter <= 0;
+                            // Pack 11-byte data packet into 3 x 32-bit words
+                            // Doppler fields zeroed when stream disabled
+                            // CFAR field zeroed when stream disabled
+                            data_pkt_word0 <= {HEADER,
+                                               range_profile_cap[31:24],
+                                               range_profile_cap[23:16],
+                                               range_profile_cap[15:8]};
+                            data_pkt_word1 <= {range_profile_cap[7:0],
+                                               stream_doppler_en ? doppler_real_cap[15:8] : 8'd0,
+                                               stream_doppler_en ? doppler_real_cap[7:0]  : 8'd0,
+                                               stream_doppler_en ? doppler_imag_cap[15:8] : 8'd0};
+                            data_pkt_word2 <= {stream_doppler_en ? doppler_imag_cap[7:0]  : 8'd0,
+                                               stream_cfar_en
+                                                    ? {(sample_counter == 12'd0), 6'b0, cfar_detection_cap}
+                                                    : {(sample_counter == 12'd0), 7'd0},
+                                               FOOTER,
+                                               8'h00};  // pad byte
+                            data_pkt_be2   <= 4'b1110;   // 3 valid bytes + 1 pad
+                            data_word_idx  <= 2'd0;
+                            current_state  <= SEND_DATA_WORD;
                        end
                    end
                end

-                SEND_HEADER: begin
-                    if (!ft601_txe) begin  // FT601 TX FIFO not empty
-                        ft601_data_oe <= 1;
-                        ft601_data_out <= {24'b0, HEADER};
-                        ft601_be <= 4'b0001;  // Only lower byte valid
-                        ft601_wr_n <= 0;     // Assert write strobe
-                        // Gap 2: skip to first enabled stream
-                        if (stream_range_en)
-                            current_state <= SEND_RANGE_DATA;
-                        else if (stream_doppler_en)
-                            current_state <= SEND_DOPPLER_DATA;
-                        else if (stream_cfar_en)
-                            current_state <= SEND_DETECTION_DATA;
-                        else
-                            current_state <= SEND_FOOTER;  // No streams — send footer only
-                    end
-                end
-                
-                SEND_RANGE_DATA: begin
+                SEND_DATA_WORD: begin
                    if (!ft601_txe) begin
                        ft601_data_oe <= 1;
-                        ft601_be <= 4'b1111;  // All bytes valid for 32-bit word
-                        
-                        case (byte_counter)
-                            0: ft601_data_out <= range_profile_cap;
-                            1: ft601_data_out <= {range_profile_cap[23:0], 8'h00};
-                            2: ft601_data_out <= {range_profile_cap[15:0], 16'h0000};
-                            3: ft601_data_out <= {range_profile_cap[7:0], 24'h000000};
-                        endcase
-                        
                        ft601_wr_n <= 0;
-                        
-                        if (byte_counter == 3) begin
-                            byte_counter <= 0;
-                            // Gap 2: skip disabled streams
-                            if (stream_doppler_en)
-                                current_state <= SEND_DOPPLER_DATA;
-                            else if (stream_cfar_en)
-                                current_state <= SEND_DETECTION_DATA;
-                            else
-                                current_state <= SEND_FOOTER;
-                        end else begin
-                            byte_counter <= byte_counter + 1;
-                        end
-                    end
-                end
-                
-                SEND_DOPPLER_DATA: begin
-                    if (!ft601_txe && doppler_data_pending) begin
-                        ft601_data_oe <= 1;
+                        case (data_word_idx)
+                            2'd0: begin
+                                ft601_data_out <= data_pkt_word0;
                                ft601_be <= 4'b1111;
-                        
-                        case (byte_counter)
-                            0: ft601_data_out <= {doppler_real_cap, doppler_imag_cap};
-                            1: ft601_data_out <= {doppler_imag_cap, doppler_real_cap[15:8], 8'h00};
-                            2: ft601_data_out <= {doppler_real_cap[7:0], doppler_imag_cap[15:8], 16'h0000};
-                            3: ft601_data_out <= {doppler_imag_cap[7:0], 24'h000000};
+                            end
+                            2'd1: begin
+                                ft601_data_out <= data_pkt_word1;
+                                ft601_be <= 4'b1111;
+                            end
+                            2'd2: begin
+                                ft601_data_out <= data_pkt_word2;
+                                ft601_be <= data_pkt_be2;
+                            end
+                            default: ;
                        endcase
-                        
-                        ft601_wr_n <= 0;
-                        
-                        if (byte_counter == 3) begin
-                            byte_counter <= 0;
-                            doppler_data_pending <= 1'b0;
-                            if (stream_cfar_en)
-                                current_state <= SEND_DETECTION_DATA;
-                            else
-                                current_state <= SEND_FOOTER;
-                        end else begin
-                            byte_counter <= byte_counter + 1;
-                        end
-                    end else if (!doppler_data_pending) begin
-                        // No doppler data available yet — skip to next stream
-                        byte_counter <= 0;
-                        if (stream_cfar_en)
-                            current_state <= SEND_DETECTION_DATA;
-                        else
-                            current_state <= SEND_FOOTER;
-                    end
-                end
-                
-                SEND_DETECTION_DATA: begin
-                    if (!ft601_txe && cfar_data_pending) begin
-                        ft601_data_oe <= 1;
-                        ft601_be <= 4'b0001;
-                        ft601_data_out <= {24'b0, 7'b0, cfar_detection_cap};
-                        ft601_wr_n <= 0;
-                        cfar_data_pending <= 1'b0;
-                        current_state <= SEND_FOOTER;
-                    end else if (!cfar_data_pending) begin
-                        // No CFAR data available yet — skip to footer
-                        current_state <= SEND_FOOTER;
-                    end
-                end
-                
-                SEND_FOOTER: begin
-                    if (!ft601_txe) begin
-                        ft601_data_oe <= 1;
-                        ft601_be <= 4'b0001;
-                        ft601_data_out <= {24'b0, FOOTER};
-                        ft601_wr_n <= 0;
+                        if (data_word_idx == 2'd2) begin
+                            data_word_idx <= 2'd0;
                            current_state <= WAIT_ACK;
+                        end else begin
+                            data_word_idx <= data_word_idx + 2'd1;
+                        end
                    end
                end

@@ -581,6 +630,14 @@ always @(posedge ft601_clk_in or negedge ft601_reset_n) begin
                WAIT_ACK: begin
                    ft601_wr_n <= 1;
                    ft601_data_oe <= 0;  // Release data bus
+                    // Clear pending flags — data consumed
+                    doppler_data_pending <= 1'b0;
+                    cfar_data_pending    <= 1'b0;
+                    // Advance frame sync counter
+                    if (sample_counter == NUM_CELLS - 12'd1)
+                        sample_counter <= 12'd0;
+                    else
+                        sample_counter <= sample_counter + 12'd1;
                    current_state <= IDLE;
                end
            endcase
@@ -613,8 +670,8 @@ ODDR #(
 `else
 // Simulation: behavioral clock forwarding
 reg ft601_clk_out_sim;
-always @(posedge ft601_clk_in or negedge ft601_reset_n) begin
-    if (!ft601_reset_n)
+always @(posedge ft601_clk_in or negedge ft601_effective_reset_n) begin
+    if (!ft601_effective_reset_n)
        ft601_clk_out_sim <= 1'b0;
    else
        ft601_clk_out_sim <= 1'b1;
@@ -36,6 +36,13 @@
 * Clock domains:
 *   clk       = 100 MHz system clock (radar data domain)
 *   ft_clk    = 60 MHz from FT2232H CLKOUT (USB FIFO domain)
+ *
+ * USB disconnect recovery:
+ *   A clock-activity watchdog in the clk domain detects when ft_clk stops
+ *   (USB cable unplugged). After ~0.65 ms of silence (65536 system clocks)
+ *   it asserts ft_clk_lost, which is OR'd into the FT-domain reset so
+ *   FSMs and FIFOs return to a clean state. When ft_clk resumes, a 2-stage
+ *   reset synchronizer deasserts the reset cleanly in the ft_clk domain.
 */

 module usb_data_interface_ft2232h (
@@ -59,7 +66,9 @@ module usb_data_interface_ft2232h (
    output reg ft_rd_n,             // Read strobe (active low)
    output reg ft_wr_n,             // Write strobe (active low)
    output reg ft_oe_n,             // Output enable (active low) — bus direction
-    output reg ft_siwu,             // Send Immediate / WakeUp
+    output reg ft_siwu,             // Send Immediate / WakeUp — UNUSED: held low.
+                                    // SIWU could flush the TX FIFO for lower latency
+                                    // but is not needed at current data rates. Deferred.

    // Clock from FT2232H (directly used — no ODDR forwarding needed)
    input wire ft_clk,              // 60 MHz from FT2232H CLKOUT
@@ -134,6 +143,7 @@ localparam [2:0] RD_IDLE       = 3'd0,
 reg [2:0] rd_state;
 reg [1:0] rd_byte_cnt;   // 0..3 for 4-byte command word
 reg [31:0] rd_shift_reg;  // Shift register to assemble 4-byte command
+reg rd_cmd_complete;      // Set when all 4 bytes received (distinguishes from abort)

 // ============================================================================
 // DATA BUS DIRECTION CONTROL
@@ -192,6 +202,70 @@ always @(posedge clk or negedge reset_n) begin
    end
 end

+// ============================================================================
+// CLOCK-ACTIVITY WATCHDOG (clk domain)
+// ============================================================================
+// Detects when ft_clk stops (USB cable unplugged). A toggle register in the
+// ft_clk domain flips every ft_clk edge. The clk domain synchronizes it and
+// checks for transitions. If no transition is seen for 2^16 = 65536 clk
+// cycles (~0.65 ms at 100 MHz), ft_clk_lost asserts.
+//
+// ft_clk_lost feeds into the effective reset for the ft_clk domain so that
+// FSMs and capture registers return to a clean state automatically.
+
+// Toggle register: flips every ft_clk edge (ft_clk domain)
+reg ft_heartbeat;
+always @(posedge ft_clk or negedge ft_reset_n) begin
+    if (!ft_reset_n)
+        ft_heartbeat <= 1'b0;
+    else
+        ft_heartbeat <= ~ft_heartbeat;
+end
+
+// Synchronize heartbeat into clk domain (2-stage)
+(* ASYNC_REG = "TRUE" *) reg [1:0] ft_hb_sync;
+reg ft_hb_prev;
+reg [15:0] ft_clk_timeout;
+reg ft_clk_lost;
+
+always @(posedge clk or negedge reset_n) begin
+    if (!reset_n) begin
+        ft_hb_sync    <= 2'b00;
+        ft_hb_prev    <= 1'b0;
+        ft_clk_timeout <= 16'd0;
+        ft_clk_lost   <= 1'b0;
+    end else begin
+        ft_hb_sync <= {ft_hb_sync[0], ft_heartbeat};
+        ft_hb_prev <= ft_hb_sync[1];
+
+        if (ft_hb_sync[1] != ft_hb_prev) begin
+            // ft_clk is alive — reset counter, clear lost flag
+            ft_clk_timeout <= 16'd0;
+            ft_clk_lost    <= 1'b0;
+        end else if (!ft_clk_lost) begin
+            if (ft_clk_timeout == 16'hFFFF)
+                ft_clk_lost <= 1'b1;
+            else
+                ft_clk_timeout <= ft_clk_timeout + 16'd1;
+        end
+    end
+end
+
+// Effective FT-domain reset: asserted by global reset OR clock loss.
+// Deassertion synchronized to ft_clk via 2-stage sync to avoid
+// metastability on the recovery edge.
+(* ASYNC_REG = "TRUE" *) reg [1:0] ft_reset_sync;
+wire ft_reset_raw_n = ft_reset_n & ~ft_clk_lost;
+
+always @(posedge ft_clk or negedge ft_reset_raw_n) begin
+    if (!ft_reset_raw_n)
+        ft_reset_sync <= 2'b00;
+    else
+        ft_reset_sync <= {ft_reset_sync[0], 1'b1};
+end
+
+wire ft_effective_reset_n = ft_reset_sync[1];
+
 // --- 3-stage synchronizers (ft_clk domain) ---
 // 3 stages for better MTBF at 60 MHz

@@ -228,12 +302,25 @@ reg cfar_detection_cap;
 reg doppler_data_pending;
 reg cfar_data_pending;

+// 1-cycle delayed range trigger.  range_valid_ft fires on the same clock
+// edge that range_profile_cap is captured (non-blocking).  If the FSM
+// reads range_profile_cap on that same edge it sees the STALE value.
+// Delaying the trigger by one cycle guarantees the capture register has
+// settled before the byte mux reads it.
+reg range_data_ready;
+
+// Frame sync: sample counter (ft_clk domain, wraps at NUM_CELLS)
+// Bit 7 of detection byte is set when sample_counter == 0 (frame start).
+// This allows the Python host to resynchronize without a protocol change.
+localparam [11:0] NUM_CELLS = 12'd2048;  // 64 range x 32 doppler
+reg [11:0] sample_counter;
+
 // Status snapshot (ft_clk domain)
 reg [31:0] status_words [0:5];

 integer si;  // status_words loop index
-always @(posedge ft_clk or negedge ft_reset_n) begin
-    if (!ft_reset_n) begin
+always @(posedge ft_clk or negedge ft_effective_reset_n) begin
+    if (!ft_effective_reset_n) begin
        range_toggle_sync   <= 3'b000;
        doppler_toggle_sync <= 3'b000;
        cfar_toggle_sync    <= 3'b000;
@@ -246,6 +333,7 @@ always @(posedge ft_clk or negedge ft_reset_n) begin
        doppler_real_cap    <= 16'd0;
        doppler_imag_cap    <= 16'd0;
        cfar_detection_cap  <= 1'b0;
+        range_data_ready    <= 1'b0;
        // Default to range-only on reset (prevents write FSM deadlock)
        stream_ctrl_sync_0  <= 3'b001;
        stream_ctrl_sync_1  <= 3'b001;
@@ -279,6 +367,10 @@ always @(posedge ft_clk or negedge ft_reset_n) begin
        if (cfar_valid_ft)
            cfar_detection_cap <= cfar_detection_hold;

+        // 1-cycle delayed trigger: ensures range_profile_cap has settled
+        // before the FSM reads it via the byte mux.
+        range_data_ready <= range_valid_ft;
+
        // Status snapshot on request
        if (status_req_ft) begin
            // Word 0: {0xFF[31:24], mode[23:22], stream[21:19], 3'b000[18:16], threshold[15:0]}
@@ -315,11 +407,16 @@ always @(*) begin
        5'd2:  data_pkt_byte = range_profile_cap[23:16];
        5'd3:  data_pkt_byte = range_profile_cap[15:8];
        5'd4:  data_pkt_byte = range_profile_cap[7:0];     // range LSB
-        5'd5:  data_pkt_byte = doppler_real_cap[15:8];      // doppler_real MSB
-        5'd6:  data_pkt_byte = doppler_real_cap[7:0];       // doppler_real LSB
-        5'd7:  data_pkt_byte = doppler_imag_cap[15:8];      // doppler_imag MSB
-        5'd8:  data_pkt_byte = doppler_imag_cap[7:0];       // doppler_imag LSB
-        5'd9:  data_pkt_byte = {7'b0, cfar_detection_cap};  // detection
+        // Doppler fields: zero when stream_doppler_en is off
+        5'd5:  data_pkt_byte = stream_doppler_en ? doppler_real_cap[15:8]  : 8'd0;
+        5'd6:  data_pkt_byte = stream_doppler_en ? doppler_real_cap[7:0]   : 8'd0;
+        5'd7:  data_pkt_byte = stream_doppler_en ? doppler_imag_cap[15:8]  : 8'd0;
+        5'd8:  data_pkt_byte = stream_doppler_en ? doppler_imag_cap[7:0]   : 8'd0;
+        // Detection field: zero when stream_cfar_en is off
+        // Bit 7 = frame_start flag (sample_counter == 0), bit 0 = cfar_detection
+        5'd9:  data_pkt_byte = stream_cfar_en
+                   ? {(sample_counter == 12'd0), 6'b0, cfar_detection_cap}
+                   : {(sample_counter == 12'd0), 7'd0};
        5'd10: data_pkt_byte = FOOTER;
        default: data_pkt_byte = 8'h00;
    endcase
@@ -376,12 +473,13 @@ end
 // Write FSM and Read FSM share the bus. Write FSM operates when Read FSM
 // is idle. Read FSM takes priority when host has data available.

-always @(posedge ft_clk or negedge ft_reset_n) begin
-    if (!ft_reset_n) begin
+always @(posedge ft_clk or negedge ft_effective_reset_n) begin
+    if (!ft_effective_reset_n) begin
        wr_state       <= WR_IDLE;
        wr_byte_idx    <= 5'd0;
        rd_state       <= RD_IDLE;
        rd_byte_cnt    <= 2'd0;
+        rd_cmd_complete <= 1'b0;
        rd_shift_reg   <= 32'd0;
        ft_data_out    <= 8'd0;
        ft_data_oe     <= 1'b0;
@@ -396,6 +494,7 @@ always @(posedge ft_clk or negedge ft_reset_n) begin
        cmd_value      <= 16'd0;
        doppler_data_pending <= 1'b0;
        cfar_data_pending    <= 1'b0;
+        sample_counter       <= 12'd0;
    end else begin
        // Default: clear one-shot signals
        cmd_valid <= 1'b0;
@@ -439,6 +538,7 @@ always @(posedge ft_clk or negedge ft_reset_n) begin
                    // All 4 bytes received
                    ft_rd_n         <= 1'b1;
                    rd_byte_cnt     <= 2'd0;
+                    rd_cmd_complete <= 1'b1;
                    rd_state        <= RD_DEASSERT;
                end else begin
                    rd_byte_cnt <= rd_byte_cnt + 2'd1;
@@ -447,6 +547,7 @@ always @(posedge ft_clk or negedge ft_reset_n) begin
                        // Host ran out of data mid-command — abort
                        ft_rd_n         <= 1'b1;
                        rd_byte_cnt     <= 2'd0;
+                        rd_cmd_complete <= 1'b0;
                        rd_state        <= RD_DEASSERT;
                    end
                end
@@ -456,7 +557,8 @@ always @(posedge ft_clk or negedge ft_reset_n) begin
                // Deassert OE (1 cycle after RD deasserted)
                ft_oe_n  <= 1'b1;
                // Only process if we received a full 4-byte command
-                if (rd_byte_cnt == 2'd0) begin
+                if (rd_cmd_complete) begin
+                    rd_cmd_complete <= 1'b0;
                    rd_state <= RD_PROCESS;
                end else begin
                    // Incomplete command — discard
@@ -491,8 +593,13 @@ always @(posedge ft_clk or negedge ft_reset_n) begin
                        wr_state    <= WR_STATUS_SEND;
                        wr_byte_idx <= 5'd0;
                    end
-                    // Trigger on range_valid edge (primary data trigger)
-                    else if (range_valid_ft && stream_range_en) begin
+                    // Trigger on range_data_ready (1 cycle after range_valid_ft)
+                    // so that range_profile_cap has settled from the CDC block.
+                    // Gate on pending flags: only send when all enabled
+                    // streams have fresh data (avoids stale doppler/CFAR)
+                    else if (range_data_ready && stream_range_en
+                             && (!stream_doppler_en || doppler_data_pending)
+                             && (!stream_cfar_en    || cfar_data_pending)) begin
                        if (ft_rxf_n) begin  // No host read pending
                            wr_state    <= WR_DATA_SEND;
                            wr_byte_idx <= 5'd0;
@@ -538,6 +645,11 @@ always @(posedge ft_clk or negedge ft_reset_n) begin
                    // Clear pending flags — data consumed
                    doppler_data_pending <= 1'b0;
                    cfar_data_pending    <= 1'b0;
+                    // Advance frame sync counter
+                    if (sample_counter == NUM_CELLS - 12'd1)
+                        sample_counter <= 12'd0;
+                    else
+                        sample_counter <= sample_counter + 12'd1;
                    wr_state   <= WR_IDLE;
                end

@@ -1,3 +1,9 @@
+# =============================================================================
+# DEPRECATED: GUI V6 is superseded by GUI_V65_Tk (tkinter) and V7 (PyQt6).
+# This file is retained for reference only. Do not use for new development.
+# Removal planned for next major release.
+# =============================================================================
+
 import tkinter as tk
 from tkinter import ttk, messagebox
 import threading
@@ -59,7 +59,7 @@ except (ModuleNotFoundError, ImportError):

 # Import protocol layer (no GUI deps)
 from radar_protocol import (
-    RadarProtocol, FT2232HConnection,
+    RadarProtocol, FT2232HConnection, FT601Connection,
    DataRecorder, RadarAcquisition,
    RadarFrame, StatusResponse,
    NUM_RANGE_BINS, NUM_DOPPLER_BINS, WATERFALL_DEPTH,
@@ -98,9 +98,10 @@ class DemoTarget:

    __slots__ = ("azimuth", "classification", "id", "range_m", "snr", "velocity")

-    # Physical range grid: 64 bins x ~4.8 m/bin = ~307 m max
-    _RANGE_PER_BIN: float = (3e8 / (2 * 500e6)) * 16  # ~4.8 m
-    _MAX_RANGE: float = _RANGE_PER_BIN * NUM_RANGE_BINS  # ~307 m
+    # Physical range grid: 64 bins x ~24 m/bin = ~1536 m max
+    # Bin spacing = c / (2 * Fs) * decimation, where Fs = 100 MHz DDC output.
+    _RANGE_PER_BIN: float = (3e8 / (2 * 100e6)) * 16  # ~24 m
+    _MAX_RANGE: float = _RANGE_PER_BIN * NUM_RANGE_BINS  # ~1536 m

    def __init__(self, tid: int):
        self.id = tid
@@ -187,10 +188,10 @@ class DemoSimulator:
        mag = np.zeros((NUM_RANGE_BINS, NUM_DOPPLER_BINS), dtype=np.float64)
        det = np.zeros((NUM_RANGE_BINS, NUM_DOPPLER_BINS), dtype=np.uint8)

-        # Range/Doppler scaling (approximate)
-        range_per_bin = (3e8 / (2 * 500e6)) * 16  # ~4.8 m/bin
+        # Range/Doppler scaling: bin spacing = c/(2*Fs)*decimation
+        range_per_bin = (3e8 / (2 * 100e6)) * 16  # ~24 m/bin
        max_range = range_per_bin * NUM_RANGE_BINS
-        vel_per_bin = 1.484  # m/s per Doppler bin (from WaveformConfig)
+        vel_per_bin = 5.34  # m/s per Doppler bin (radar_scene.py: lam/(2*16*PRI))

        for t in targets:
            if t.range_m > max_range or t.range_m < 0:
@@ -385,13 +386,14 @@ class RadarDashboard:
    UPDATE_INTERVAL_MS = 100  # 10 Hz display refresh

    # Radar parameters used for range-axis scaling.
-    BANDWIDTH = 500e6        # Hz — chirp bandwidth
+    SAMPLE_RATE = 100e6      # Hz — DDC output I/Q rate (matched filter input)
    C = 3e8                  # m/s — speed of light

-    def __init__(self, root: tk.Tk, connection: FT2232HConnection,
+    def __init__(self, root: tk.Tk, mock: bool,
                 recorder: DataRecorder, device_index: int = 0):
        self.root = root
-        self.conn = connection
+        self._mock = mock
+        self.conn: FT2232HConnection | FT601Connection | None = None
        self.recorder = recorder
        self.device_index = device_index

@@ -485,6 +487,16 @@ class RadarDashboard:
                                       style="Accent.TButton")
        self.btn_connect.pack(side="right", padx=4)

+        # USB Interface selector (production FT2232H / premium FT601)
+        self._usb_iface_var = tk.StringVar(value="FT2232H (Production)")
+        self.cmb_usb_iface = ttk.Combobox(
+            top, textvariable=self._usb_iface_var,
+            values=["FT2232H (Production)", "FT601 (Premium)"],
+            state="readonly", width=20,
+        )
+        self.cmb_usb_iface.pack(side="right", padx=4)
+        ttk.Label(top, text="USB:", font=("Menlo", 10)).pack(side="right")
+
        self.btn_record = ttk.Button(top, text="Record", command=self._on_record)
        self.btn_record.pack(side="right", padx=4)

@@ -515,9 +527,8 @@ class RadarDashboard:

    def _build_display_tab(self, parent):
        # Compute physical axis limits
-        range_res = self.C / (2.0 * self.BANDWIDTH)  # ~0.3 m per FFT bin
-        # After decimation 1024→64, each range bin = 16 FFT bins
-        range_per_bin = range_res * 16
+        # Bin spacing = c / (2 * Fs_ddc) for matched-filter processing.
+        range_per_bin = self.C / (2.0 * self.SAMPLE_RATE) * 16  # ~24 m
        max_range = range_per_bin * NUM_RANGE_BINS

        doppler_bin_lo = 0
@@ -1018,15 +1029,17 @@ class RadarDashboard:

    # ------------------------------------------------------------ Actions
    def _on_connect(self):
-        if self.conn.is_open:
+        if self.conn is not None and self.conn.is_open:
            # Disconnect
            if self._acq_thread is not None:
                self._acq_thread.stop()
                self._acq_thread.join(timeout=2)
                self._acq_thread = None
            self.conn.close()
+            self.conn = None
            self.lbl_status.config(text="DISCONNECTED", foreground=RED)
            self.btn_connect.config(text="Connect")
+            self.cmb_usb_iface.config(state="readonly")
            log.info("Disconnected")
            return

@@ -1036,6 +1049,16 @@ class RadarDashboard:
        if self._replay_active:
            self._replay_stop()

+        # Create connection based on USB Interface selector
+        iface = self._usb_iface_var.get()
+        if "FT601" in iface:
+            self.conn = FT601Connection(mock=self._mock)
+        else:
+            self.conn = FT2232HConnection(mock=self._mock)
+
+        # Disable interface selector while connecting/connected
+        self.cmb_usb_iface.config(state="disabled")
+
        # Open connection in a background thread to avoid blocking the GUI
        self.lbl_status.config(text="CONNECTING...", foreground=YELLOW)
        self.btn_connect.config(state="disabled")
@@ -1062,6 +1085,8 @@ class RadarDashboard:
        else:
            self.lbl_status.config(text="CONNECT FAILED", foreground=RED)
            self.btn_connect.config(text="Connect")
+            self.cmb_usb_iface.config(state="readonly")
+            self.conn = None

    def _on_record(self):
        if self.recorder.recording:
@@ -1110,6 +1135,9 @@ class RadarDashboard:
                 f"Opcode 0x{opcode:02X} is hardware-only (ignored in replay)"))
            return
        cmd = RadarProtocol.build_command(opcode, value)
+        if self.conn is None:
+            log.warning("No connection — command not sent")
+            return
        ok = self.conn.write(cmd)
        log.info(f"CMD 0x{opcode:02X} val={value} ({'OK' if ok else 'FAIL'})")

@@ -1148,7 +1176,7 @@ class RadarDashboard:
        if self._replay_active or self._replay_ctrl is not None:
            self._replay_stop()
        if self._acq_thread is not None:
-            if self.conn.is_open:
+            if self.conn is not None and self.conn.is_open:
                self._on_connect()  # disconnect
            else:
                # Connection dropped unexpectedly — just clean up the thread
@@ -1547,17 +1575,17 @@ def main():
    args = parser.parse_args()

    if args.live:
-        conn = FT2232HConnection(mock=False)
+        mock = False
        mode_str = "LIVE"
    else:
-        conn = FT2232HConnection(mock=True)
+        mock = True
        mode_str = "MOCK"

    recorder = DataRecorder()

    root = tk.Tk()

-    dashboard = RadarDashboard(root, conn, recorder, device_index=args.device)
+    dashboard = RadarDashboard(root, mock, recorder, device_index=args.device)

    if args.record:
        filepath = os.path.join(
@@ -1582,8 +1610,8 @@ def main():
        if dashboard._acq_thread is not None:
            dashboard._acq_thread.stop()
            dashboard._acq_thread.join(timeout=2)
-        if conn.is_open:
-            conn.close()
+        if dashboard.conn is not None and dashboard.conn.is_open:
+            dashboard.conn.close()
        if recorder.recording:
            recorder.stop()
        root.destroy()
@@ -1,5 +1,11 @@
 #!/usr/bin/env python3

+# =============================================================================
+# DEPRECATED: GUI V6 Demo is superseded by GUI_V65_Tk and V7.
+# This file is retained for reference only. Do not use for new development.
+# Removal planned for next major release.
+# =============================================================================
+
 """
 Radar System GUI - Fully Functional Demo Version
 All buttons work, simulated radar data is generated in real-time
@@ -6,7 +6,7 @@ GUI_V4 ==> Added pitch correction

 GUI_V5 ==> Added Mercury Color

-GUI_V6 ==> Added USB3 FT601 support
+GUI_V6 ==> Added USB3 FT601 support  [DEPRECATED — superseded by V65/V7]

 GUI_V65_Tk ==> Board bring-up dashboard (FT2232H reader, real-time R-D heatmap, CFAR overlay, waterfall, host commands, HDF5 recording, replay, demo mode)
 radar_protocol ==> Protocol layer (packet parsing, command building, FT2232H connection, data recorder, acquisition thread)
@@ -6,6 +6,7 @@ Pure-logic module for USB packet parsing and command building.
 No GUI dependencies — safe to import from tests and headless scripts.

 USB Interface: FT2232H USB 2.0 (8-bit, 50T production board) via pyftdi
+               FT601 USB 3.0 (32-bit, 200T premium board) via ftd3xx

 USB Packet Protocol (11-byte):
  TX (FPGA→Host):
@@ -22,7 +23,7 @@ import queue
 import logging
 import contextlib
 from dataclasses import dataclass, field
-from typing import Any
+from typing import Any, ClassVar
 from enum import IntEnum


@@ -200,7 +201,9 @@ class RadarProtocol:
        range_i = _to_signed16(struct.unpack_from(">H", raw, 3)[0])
        doppler_i = _to_signed16(struct.unpack_from(">H", raw, 5)[0])
        doppler_q = _to_signed16(struct.unpack_from(">H", raw, 7)[0])
-        detection = raw[9] & 0x01
+        det_byte = raw[9]
+        detection = det_byte & 0x01
+        frame_start = (det_byte >> 7) & 0x01

        return {
            "range_i": range_i,
@@ -208,6 +211,7 @@ class RadarProtocol:
            "doppler_i": doppler_i,
            "doppler_q": doppler_q,
            "detection": detection,
+            "frame_start": frame_start,
        }

    @staticmethod
@@ -433,7 +437,191 @@ class FT2232HConnection:
            pkt += struct.pack(">h", np.clip(range_i, -32768, 32767))
            pkt += struct.pack(">h", np.clip(dop_i, -32768, 32767))
            pkt += struct.pack(">h", np.clip(dop_q, -32768, 32767))
-            pkt.append(detection & 0x01)
+            # Bit 7 = frame_start (sample_counter == 0), bit 0 = detection
+            det_byte = (detection & 0x01) | (0x80 if idx == 0 else 0x00)
+            pkt.append(det_byte)
+            pkt.append(FOOTER_BYTE)
+
+            buf += pkt
+
+        self._mock_seq_idx = (start_idx + num_packets) % NUM_CELLS
+        return bytes(buf)
+
+
+# ============================================================================
+# FT601 USB 3.0 Connection (premium board only)
+# ============================================================================
+
+# Optional ftd3xx import (FTDI's proprietary driver for FT60x USB 3.0 chips).
+# pyftdi does NOT support FT601 — it only handles USB 2.0 chips (FT232H, etc.)
+try:
+    import ftd3xx  # type: ignore[import-untyped]
+    FTD3XX_AVAILABLE = True
+    _Ftd3xxError: type = ftd3xx.FTD3XXError  # type: ignore[attr-defined]
+except ImportError:
+    FTD3XX_AVAILABLE = False
+    _Ftd3xxError = OSError  # fallback for type-checking; never raised
+
+
+class FT601Connection:
+    """
+    FT601 USB 3.0 SuperSpeed FIFO bridge — premium board only.
+
+    The FT601 has a 32-bit data bus and runs at 100 MHz.
+    VID:PID = 0x0403:0x6030 or 0x6031 (FTDI FT60x).
+
+    Requires the ``ftd3xx`` library (``pip install ftd3xx`` on Windows,
+    or ``libft60x`` on Linux). This is FTDI's proprietary USB 3.0 driver;
+    ``pyftdi`` only supports USB 2.0 and will NOT work with FT601.
+
+    Public contract matches FT2232HConnection so callers can swap freely.
+    """
+
+    VID = 0x0403
+    PID_LIST: ClassVar[list[int]] = [0x6030, 0x6031]
+
+    def __init__(self, mock: bool = True):
+        self._mock = mock
+        self._dev = None
+        self._lock = threading.Lock()
+        self.is_open = False
+        # Mock state (reuses same synthetic data pattern)
+        self._mock_frame_num = 0
+        self._mock_rng = np.random.RandomState(42)
+
+    def open(self, device_index: int = 0) -> bool:
+        if self._mock:
+            self.is_open = True
+            log.info("FT601 mock device opened (no hardware)")
+            return True
+
+        if not FTD3XX_AVAILABLE:
+            log.error(
+                "ftd3xx library required for FT601 hardware — "
+                "install with: pip install ftd3xx"
+            )
+            return False
+
+        try:
+            self._dev = ftd3xx.create(device_index, ftd3xx.OPEN_BY_INDEX)
+            if self._dev is None:
+                log.error("No FT601 device found at index %d", device_index)
+                return False
+            # Verify chip configuration — only reconfigure if needed.
+            # setChipConfiguration triggers USB re-enumeration, which
+            # invalidates the device handle and requires a re-open cycle.
+            cfg = self._dev.getChipConfiguration()
+            needs_reconfig = (
+                cfg.FIFOMode != 0            # 245 FIFO mode
+                or cfg.ChannelConfig != 0    # 1 channel, 32-bit
+                or cfg.OptionalFeatureSupport != 0
+            )
+            if needs_reconfig:
+                cfg.FIFOMode = 0
+                cfg.ChannelConfig = 0
+                cfg.OptionalFeatureSupport = 0
+                self._dev.setChipConfiguration(cfg)
+                # Device re-enumerates — close stale handle, wait, re-open
+                self._dev.close()
+                self._dev = None
+                import time
+                time.sleep(2.0)  # wait for USB re-enumeration
+                self._dev = ftd3xx.create(device_index, ftd3xx.OPEN_BY_INDEX)
+                if self._dev is None:
+                    log.error("FT601 not found after reconfiguration")
+                    return False
+                log.info("FT601 reconfigured and re-opened (index %d)", device_index)
+            self.is_open = True
+            log.info("FT601 device opened (index %d)", device_index)
+            return True
+        except (OSError, _Ftd3xxError) as e:
+            log.error("FT601 open failed: %s", e)
+            self._dev = None
+            return False
+
+    def close(self):
+        if self._dev is not None:
+            with contextlib.suppress(Exception):
+                self._dev.close()
+            self._dev = None
+        self.is_open = False
+
+    def read(self, size: int = 4096) -> bytes | None:
+        """Read raw bytes from FT601. Returns None on error/timeout."""
+        if not self.is_open:
+            return None
+
+        if self._mock:
+            return self._mock_read(size)
+
+        with self._lock:
+            try:
+                data = self._dev.readPipe(0x82, size, raw=True)
+                return bytes(data) if data else None
+            except (OSError, _Ftd3xxError) as e:
+                log.error("FT601 read error: %s", e)
+                return None
+
+    def write(self, data: bytes) -> bool:
+        """Write raw bytes to FT601. Data must be 4-byte aligned for 32-bit bus."""
+        if not self.is_open:
+            return False
+
+        if self._mock:
+            log.info(f"FT601 mock write: {data.hex()}")
+            return True
+
+        # Pad to 4-byte alignment (FT601 32-bit bus requirement).
+        # NOTE: Radar commands are already 4 bytes, so this should be a no-op.
+        remainder = len(data) % 4
+        if remainder:
+            data = data + b"\x00" * (4 - remainder)
+
+        with self._lock:
+            try:
+                written = self._dev.writePipe(0x02, data, raw=True)
+                return written == len(data)
+            except (OSError, _Ftd3xxError) as e:
+                log.error("FT601 write error: %s", e)
+                return False
+
+    def _mock_read(self, size: int) -> bytes:
+        """Generate synthetic radar packets (same pattern as FT2232H mock)."""
+        time.sleep(0.05)
+        self._mock_frame_num += 1
+
+        buf = bytearray()
+        num_packets = min(NUM_CELLS, size // DATA_PACKET_SIZE)
+        start_idx = getattr(self, "_mock_seq_idx", 0)
+
+        for n in range(num_packets):
+            idx = (start_idx + n) % NUM_CELLS
+            rbin = idx // NUM_DOPPLER_BINS
+            dbin = idx % NUM_DOPPLER_BINS
+
+            range_i = int(self._mock_rng.normal(0, 100))
+            range_q = int(self._mock_rng.normal(0, 100))
+            if abs(rbin - 20) < 3:
+                range_i += 5000
+                range_q += 3000
+
+            dop_i = int(self._mock_rng.normal(0, 50))
+            dop_q = int(self._mock_rng.normal(0, 50))
+            if abs(rbin - 20) < 3 and abs(dbin - 8) < 2:
+                dop_i += 8000
+                dop_q += 4000
+
+            detection = 1 if (abs(rbin - 20) < 2 and abs(dbin - 8) < 2) else 0
+
+            pkt = bytearray()
+            pkt.append(HEADER_BYTE)
+            pkt += struct.pack(">h", np.clip(range_q, -32768, 32767))
+            pkt += struct.pack(">h", np.clip(range_i, -32768, 32767))
+            pkt += struct.pack(">h", np.clip(dop_i, -32768, 32767))
+            pkt += struct.pack(">h", np.clip(dop_q, -32768, 32767))
+            # Bit 7 = frame_start (sample_counter == 0), bit 0 = detection
+            det_byte = (detection & 0x01) | (0x80 if idx == 0 else 0x00)
+            pkt.append(det_byte)
            pkt.append(FOOTER_BYTE)

            buf += pkt
@@ -600,6 +788,12 @@ class RadarAcquisition(threading.Thread):
            if sample.get("detection", 0):
                self._frame.detections[rbin, dbin] = 1
                self._frame.detection_count += 1
+            # Accumulate FPGA range profile data (matched-filter output)
+            # Each sample carries the range_i/range_q for this range bin.
+            # Accumulate magnitude across Doppler bins for the range profile.
+            ri = int(sample.get("range_i", 0))
+            rq = int(sample.get("range_q", 0))
+            self._frame.range_profile[rbin] += abs(ri) + abs(rq)

        self._sample_idx += 1

@@ -607,11 +801,11 @@ class RadarAcquisition(threading.Thread):
            self._finalize_frame()

    def _finalize_frame(self):
-        """Complete frame: compute range profile, push to queue, record."""
+        """Complete frame: push to queue, record."""
        self._frame.timestamp = time.time()
        self._frame.frame_number = self._frame_num
-        # Range profile = sum of magnitude across Doppler bins
-        self._frame.range_profile = np.sum(self._frame.magnitude, axis=1)
+        # range_profile is already accumulated from FPGA range_i/range_q
+        # data in _ingest_sample(). No need to synthesize from doppler magnitude.

        # Push to display queue (drop old if backed up)
        try:
@@ -16,7 +16,7 @@ import unittest
 import numpy as np

 from radar_protocol import (
-    RadarProtocol, FT2232HConnection, DataRecorder, RadarAcquisition,
+    RadarProtocol, FT2232HConnection, FT601Connection, DataRecorder, RadarAcquisition,
    RadarFrame, StatusResponse, Opcode,
    HEADER_BYTE, FOOTER_BYTE, STATUS_HEADER_BYTE,
    NUM_RANGE_BINS, NUM_DOPPLER_BINS,
@@ -312,6 +312,61 @@ class TestFT2232HConnection(unittest.TestCase):
        self.assertFalse(conn.write(b"\x00\x00\x00\x00"))


+class TestFT601Connection(unittest.TestCase):
+    """Test mock FT601 connection (mirrors FT2232H tests)."""
+
+    def test_mock_open_close(self):
+        conn = FT601Connection(mock=True)
+        self.assertTrue(conn.open())
+        self.assertTrue(conn.is_open)
+        conn.close()
+        self.assertFalse(conn.is_open)
+
+    def test_mock_read_returns_data(self):
+        conn = FT601Connection(mock=True)
+        conn.open()
+        data = conn.read(4096)
+        self.assertIsNotNone(data)
+        self.assertGreater(len(data), 0)
+        conn.close()
+
+    def test_mock_read_contains_valid_packets(self):
+        """Mock data should contain parseable data packets."""
+        conn = FT601Connection(mock=True)
+        conn.open()
+        raw = conn.read(4096)
+        packets = RadarProtocol.find_packet_boundaries(raw)
+        self.assertGreater(len(packets), 0)
+        for start, end, ptype in packets:
+            if ptype == "data":
+                result = RadarProtocol.parse_data_packet(raw[start:end])
+                self.assertIsNotNone(result)
+        conn.close()
+
+    def test_mock_write(self):
+        conn = FT601Connection(mock=True)
+        conn.open()
+        cmd = RadarProtocol.build_command(0x01, 1)
+        self.assertTrue(conn.write(cmd))
+        conn.close()
+
+    def test_write_pads_to_4_bytes(self):
+        """FT601 write() should pad data to 4-byte alignment."""
+        conn = FT601Connection(mock=True)
+        conn.open()
+        # 3-byte payload should be padded internally (no error)
+        self.assertTrue(conn.write(b"\x01\x02\x03"))
+        conn.close()
+
+    def test_read_when_closed(self):
+        conn = FT601Connection(mock=True)
+        self.assertIsNone(conn.read())
+
+    def test_write_when_closed(self):
+        conn = FT601Connection(mock=True)
+        self.assertFalse(conn.write(b"\x00\x00\x00\x00"))
+
+
 class TestDataRecorder(unittest.TestCase):
    """Test HDF5 recording (skipped if h5py not available)."""

@@ -65,9 +65,9 @@ class TestRadarSettings(unittest.TestCase):

    def test_defaults(self):
        s = _models().RadarSettings()
-        self.assertEqual(s.system_frequency, 10e9)
-        self.assertEqual(s.coverage_radius, 50000)
-        self.assertEqual(s.max_distance, 50000)
+        self.assertEqual(s.system_frequency, 10.5e9)
+        self.assertEqual(s.coverage_radius, 1536)
+        self.assertEqual(s.max_distance, 1536)


 class TestGPSData(unittest.TestCase):
@@ -425,26 +425,28 @@ class TestWaveformConfig(unittest.TestCase):
    def test_defaults(self):
        from v7.models import WaveformConfig
        wc = WaveformConfig()
-        self.assertEqual(wc.sample_rate_hz, 4e6)
-        self.assertEqual(wc.bandwidth_hz, 500e6)
-        self.assertEqual(wc.chirp_duration_s, 300e-6)
-        self.assertEqual(wc.center_freq_hz, 10.525e9)
+        self.assertEqual(wc.sample_rate_hz, 100e6)
+        self.assertEqual(wc.bandwidth_hz, 20e6)
+        self.assertEqual(wc.chirp_duration_s, 30e-6)
+        self.assertEqual(wc.pri_s, 167e-6)
+        self.assertEqual(wc.center_freq_hz, 10.5e9)
        self.assertEqual(wc.n_range_bins, 64)
        self.assertEqual(wc.n_doppler_bins, 32)
+        self.assertEqual(wc.chirps_per_subframe, 16)
        self.assertEqual(wc.fft_size, 1024)
        self.assertEqual(wc.decimation_factor, 16)

    def test_range_resolution(self):
-        """range_resolution_m should be ~5.62 m/bin with ADI defaults."""
+        """range_resolution_m should be ~23.98 m/bin (matched filter, 100 MSPS)."""
        from v7.models import WaveformConfig
        wc = WaveformConfig()
-        self.assertAlmostEqual(wc.range_resolution_m, 5.621, places=1)
+        self.assertAlmostEqual(wc.range_resolution_m, 23.983, places=1)

    def test_velocity_resolution(self):
-        """velocity_resolution_mps should be ~1.484 m/s/bin."""
+        """velocity_resolution_mps should be ~5.34 m/s/bin (PRI=167us, 16 chirps)."""
        from v7.models import WaveformConfig
        wc = WaveformConfig()
-        self.assertAlmostEqual(wc.velocity_resolution_mps, 1.484, places=2)
+        self.assertAlmostEqual(wc.velocity_resolution_mps, 5.343, places=1)

    def test_max_range(self):
        """max_range_m = range_resolution * n_range_bins."""
@@ -466,7 +468,7 @@ class TestWaveformConfig(unittest.TestCase):
        """Non-default parameters correctly change derived values."""
        from v7.models import WaveformConfig
        wc1 = WaveformConfig()
-        wc2 = WaveformConfig(bandwidth_hz=1e9)  # double BW → halve range res
+        wc2 = WaveformConfig(sample_rate_hz=200e6)  # double Fs → halve range bin
        self.assertAlmostEqual(wc2.range_resolution_m, wc1.range_resolution_m / 2, places=2)

    def test_zero_center_freq_velocity(self):
@@ -925,9 +927,9 @@ class TestExtractTargetsFromFrame(unittest.TestCase):
        """Detection at range bin 10 → range = 10 * range_resolution."""
        from v7.processing import extract_targets_from_frame
        frame = self._make_frame(det_cells=[(10, 16)])  # dbin=16 = center → vel=0
-        targets = extract_targets_from_frame(frame, range_resolution=5.621)
+        targets = extract_targets_from_frame(frame, range_resolution=23.983)
        self.assertEqual(len(targets), 1)
-        self.assertAlmostEqual(targets[0].range, 10 * 5.621, places=2)
+        self.assertAlmostEqual(targets[0].range, 10 * 23.983, places=1)
        self.assertAlmostEqual(targets[0].velocity, 0.0, places=2)

    def test_velocity_sign(self):
@@ -26,6 +26,7 @@ from .models import (
 # Hardware interfaces — production protocol via radar_protocol.py
 from .hardware import (
    FT2232HConnection,
+    FT601Connection,
    RadarProtocol,
    Opcode,
    RadarAcquisition,
@@ -89,7 +90,7 @@ __all__ = [  # noqa: RUF022
    "USB_AVAILABLE", "FTDI_AVAILABLE", "SCIPY_AVAILABLE",
    "SKLEARN_AVAILABLE", "FILTERPY_AVAILABLE",
    # hardware — production FPGA protocol
-    "FT2232HConnection", "RadarProtocol", "Opcode",
+    "FT2232HConnection", "FT601Connection", "RadarProtocol", "Opcode",
    "RadarAcquisition", "RadarFrame", "StatusResponse", "DataRecorder",
    "STM32USBInterface",
    # processing
@@ -13,13 +13,14 @@ RadarDashboard is a QMainWindow with six tabs:
  6. Settings    — Host-side DSP parameters + About section

 Uses production radar_protocol.py for all FPGA communication:
-  - FT2232HConnection for real hardware
+  - FT2232HConnection for production board (FT2232H USB 2.0)
+  - FT601Connection for premium board (FT601 USB 3.0) — selectable from GUI
  - Unified replay via SoftwareFPGA + ReplayEngine + ReplayWorker
  - Mock mode (FT2232HConnection(mock=True)) for development

 The old STM32 magic-packet start flow has been removed. FPGA registers
 are controlled directly via 4-byte {opcode, addr, value_hi, value_lo}
-commands sent over FT2232H.
+commands sent over FT2232H or FT601.
 """

 from __future__ import annotations
@@ -55,6 +56,7 @@ from .models import (
 )
 from .hardware import (
    FT2232HConnection,
+    FT601Connection,
    RadarProtocol,
    RadarFrame,
    StatusResponse,
@@ -142,7 +144,7 @@ class RadarDashboard(QMainWindow):
        )

        # Hardware interfaces — production protocol
-        self._connection: FT2232HConnection | None = None
+        self._connection: FT2232HConnection | FT601Connection | None = None
        self._stm32 = STM32USBInterface()
        self._recorder = DataRecorder()

@@ -364,7 +366,7 @@ class RadarDashboard(QMainWindow):
        # Row 0: connection mode + device combos + buttons
        ctrl_layout.addWidget(QLabel("Mode:"), 0, 0)
        self._mode_combo = QComboBox()
-        self._mode_combo.addItems(["Mock", "Live FT2232H", "Replay"])
+        self._mode_combo.addItems(["Mock", "Live", "Replay"])
        self._mode_combo.setCurrentIndex(0)
        ctrl_layout.addWidget(self._mode_combo, 0, 1)

@@ -377,6 +379,13 @@ class RadarDashboard(QMainWindow):
        refresh_btn.clicked.connect(self._refresh_devices)
        ctrl_layout.addWidget(refresh_btn, 0, 4)

+        # USB Interface selector (production FT2232H / premium FT601)
+        ctrl_layout.addWidget(QLabel("USB Interface:"), 0, 5)
+        self._usb_iface_combo = QComboBox()
+        self._usb_iface_combo.addItems(["FT2232H (Production)", "FT601 (Premium)"])
+        self._usb_iface_combo.setCurrentIndex(0)
+        ctrl_layout.addWidget(self._usb_iface_combo, 0, 6)
+
        self._start_btn = QPushButton("Start Radar")
        self._start_btn.setStyleSheet(
            f"QPushButton {{ background-color: {DARK_SUCCESS}; color: white; font-weight: bold; }}"
@@ -1001,7 +1010,8 @@ class RadarDashboard(QMainWindow):
        self._conn_ft2232h = self._make_status_label("FT2232H")
        self._conn_stm32 = self._make_status_label("STM32 USB")

-        conn_layout.addWidget(QLabel("FT2232H:"), 0, 0)
+        self._conn_usb_label = QLabel("USB Data:")
+        conn_layout.addWidget(self._conn_usb_label, 0, 0)
        conn_layout.addWidget(self._conn_ft2232h, 0, 1)
        conn_layout.addWidget(QLabel("STM32 USB:"), 1, 0)
        conn_layout.addWidget(self._conn_stm32, 1, 1)
@@ -1167,7 +1177,7 @@ class RadarDashboard(QMainWindow):
        about_lbl = QLabel(
            "<b>AERIS-10 Radar System V7</b><br>"
            "PyQt6 Edition with Embedded Leaflet Map<br><br>"
-            "<b>Data Interface:</b> FT2232H USB 2.0 (production protocol)<br>"
+            "<b>Data Interface:</b> FT2232H USB 2.0 (production) / FT601 USB 3.0 (premium)<br>"
            "<b>FPGA Protocol:</b> 4-byte register commands, 0xAA/0xBB packets<br>"
            "<b>Map:</b> OpenStreetMap + Leaflet.js<br>"
            "<b>Framework:</b> PyQt6 + QWebEngine<br>"
@@ -1224,7 +1234,7 @@ class RadarDashboard(QMainWindow):
    # =====================================================================

    def _send_fpga_cmd(self, opcode: int, value: int):
-        """Send a 4-byte register command to the FPGA via FT2232H."""
+        """Send a 4-byte register command to the FPGA via USB (FT2232H or FT601)."""
        if self._connection is None or not self._connection.is_open:
            logger.warning(f"Cannot send 0x{opcode:02X}={value}: no connection")
            return
@@ -1287,16 +1297,26 @@ class RadarDashboard(QMainWindow):

            if "Mock" in mode:
                self._replay_mode = False
+                iface = self._usb_iface_combo.currentText()
+                if "FT601" in iface:
+                    self._connection = FT601Connection(mock=True)
+                else:
                    self._connection = FT2232HConnection(mock=True)
                if not self._connection.open():
                    QMessageBox.critical(self, "Error", "Failed to open mock connection.")
                    return
            elif "Live" in mode:
                self._replay_mode = False
+                iface = self._usb_iface_combo.currentText()
+                if "FT601" in iface:
+                    self._connection = FT601Connection(mock=False)
+                    iface_name = "FT601"
+                else:
                    self._connection = FT2232HConnection(mock=False)
+                    iface_name = "FT2232H"
                if not self._connection.open():
                    QMessageBox.critical(self, "Error",
-                                         "Failed to open FT2232H. Check USB connection.")
+                                         f"Failed to open {iface_name}. Check USB connection.")
                    return
            elif "Replay" in mode:
                self._replay_mode = True
@@ -1368,6 +1388,7 @@ class RadarDashboard(QMainWindow):
                self._start_btn.setEnabled(False)
                self._stop_btn.setEnabled(True)
                self._mode_combo.setEnabled(False)
+                self._usb_iface_combo.setEnabled(False)
                self._demo_btn_main.setEnabled(False)
                self._demo_btn_map.setEnabled(False)
                n_frames = self._replay_engine.total_frames
@@ -1417,6 +1438,7 @@ class RadarDashboard(QMainWindow):
            self._start_btn.setEnabled(False)
            self._stop_btn.setEnabled(True)
            self._mode_combo.setEnabled(False)
+            self._usb_iface_combo.setEnabled(False)
            self._demo_btn_main.setEnabled(False)
            self._demo_btn_map.setEnabled(False)
            self._status_label_main.setText(f"Status: Running ({mode})")
@@ -1462,6 +1484,7 @@ class RadarDashboard(QMainWindow):
        self._start_btn.setEnabled(True)
        self._stop_btn.setEnabled(False)
        self._mode_combo.setEnabled(True)
+        self._usb_iface_combo.setEnabled(True)
        self._demo_btn_main.setEnabled(True)
        self._demo_btn_map.setEnabled(True)
        self._status_label_main.setText("Status: Radar stopped")
@@ -1954,6 +1977,12 @@ class RadarDashboard(QMainWindow):
        self._set_conn_indicator(self._conn_ft2232h, conn_open)
        self._set_conn_indicator(self._conn_stm32, self._stm32.is_open)

+        # Update USB label to reflect which interface is active
+        if isinstance(self._connection, FT601Connection):
+            self._conn_usb_label.setText("FT601:")
+        else:
+            self._conn_usb_label.setText("FT2232H:")
+
        gps_count = self._gps_packet_count
        if self._gps_worker:
            gps_count = self._gps_worker.gps_count
@@ -25,6 +25,7 @@ if USB_AVAILABLE:
 sys.path.insert(0, os.path.join(os.path.dirname(__file__), ".."))
 from radar_protocol import (  # noqa: F401 — re-exported for v7 package
    FT2232HConnection,
+    FT601Connection,
    RadarProtocol,
    Opcode,
    RadarAcquisition,
@@ -46,8 +47,9 @@ class STM32USBInterface:

    Used ONLY for receiving GPS data from the MCU.

-    FPGA register commands are sent via FT2232H (see FT2232HConnection
-    from radar_protocol.py). The old send_start_flag() / send_settings()
+    FPGA register commands are sent via the USB data interface — either
+    FT2232HConnection (production) or FT601Connection (premium), both
+    from radar_protocol.py. The old send_start_flag() / send_settings()
    methods have been removed — they used an incompatible magic-packet
    protocol that the FPGA does not understand.
    """
@@ -98,7 +98,7 @@ class RadarMapWidget(QWidget):
        )
        self._targets: list[RadarTarget] = []
        self._pending_targets: list[RadarTarget] | None = None
-        self._coverage_radius = 50_000   # metres
+        self._coverage_radius = 1_536   # metres (64 bins x ~24 m/bin)
        self._tile_server = TileServer.OPENSTREETMAP
        self._show_coverage = True
        self._show_trails = False
@@ -108,12 +108,12 @@ class RadarSettings:
    range_resolution and velocity_resolution should be calibrated to
    the actual waveform parameters.
    """
-    system_frequency: float = 10e9      # Hz (carrier, used for velocity calc)
-    range_resolution: float = 781.25    # Meters per range bin (default: 50km/64)
+    system_frequency: float = 10.5e9    # Hz (carrier, used for velocity calc)
+    range_resolution: float = 24.0       # Meters per range bin (c/(2*Fs)*decim)
    velocity_resolution: float = 1.0     # m/s per Doppler bin (calibrate to waveform)
-    max_distance: float = 50000         # Max detection range (m)
-    map_size: float = 50000             # Map display size (m)
-    coverage_radius: float = 50000      # Map coverage radius (m)
+    max_distance: float = 1536           # Max detection range (m)
+    map_size: float = 2000               # Map display size (m)
+    coverage_radius: float = 1536        # Map coverage radius (m)


@dataclass
@@ -199,39 +199,46 @@ class WaveformConfig:
    Encapsulates the radar waveform so that range/velocity resolution
    can be derived automatically instead of hardcoded in RadarSettings.

-    Defaults match the ADI CN0566 Phaser capture parameters used in
-    the golden_reference cosim (4 MSPS, 500 MHz BW, 300 us chirp).
+    Defaults match the AERIS-10 production system parameters from
+    radar_scene.py / plfm_chirp_controller.v:
+      100 MSPS DDC output, 20 MHz chirp BW, 30 us long chirp,
+      167 us long-chirp PRI, X-band 10.5 GHz carrier.
    """

-    sample_rate_hz: float = 4e6          # ADC sample rate
-    bandwidth_hz: float = 500e6          # Chirp bandwidth
-    chirp_duration_s: float = 300e-6     # Chirp ramp time
-    center_freq_hz: float = 10.525e9     # Carrier frequency
+    sample_rate_hz: float = 100e6        # DDC output I/Q rate (matched filter input)
+    bandwidth_hz: float = 20e6           # Chirp bandwidth (not used in range calc;
+                                         # retained for time-bandwidth product / display)
+    chirp_duration_s: float = 30e-6      # Long chirp ramp time
+    pri_s: float = 167e-6               # Pulse repetition interval (chirp + listen)
+    center_freq_hz: float = 10.5e9       # Carrier frequency (radar_scene.py: F_CARRIER)
    n_range_bins: int = 64               # After decimation
-    n_doppler_bins: int = 32             # After Doppler FFT
+    n_doppler_bins: int = 32             # Total Doppler bins (2 sub-frames x 16)
+    chirps_per_subframe: int = 16        # Chirps in one Doppler sub-frame
    fft_size: int = 1024                 # Pre-decimation FFT length
    decimation_factor: int = 16          # 1024 → 64

    @property
    def range_resolution_m(self) -> float:
-        """Meters per decimated range bin (FMCW deramped baseband).
+        """Meters per decimated range bin (matched-filter pulse compression).

-        For deramped FMCW: bin spacing = c * Fs * T / (2 * N_FFT * BW).
-        After decimation the bin spacing grows by *decimation_factor*.
+        For FFT-based matched filtering, each IFFT output bin spans
+        c / (2 * Fs) in range, where Fs is the I/Q sample rate at the
+        matched-filter input (DDC output).  After decimation the bin
+        spacing grows by *decimation_factor*.
        """
        c = 299_792_458.0
-        raw_bin = (
-            c * self.sample_rate_hz * self.chirp_duration_s
-            / (2.0 * self.fft_size * self.bandwidth_hz)
-        )
+        raw_bin = c / (2.0 * self.sample_rate_hz)
        return raw_bin * self.decimation_factor

    @property
    def velocity_resolution_mps(self) -> float:
-        """m/s per Doppler bin.  lambda / (2 * n_doppler * chirp_duration)."""
+        """m/s per Doppler bin.
+
+        lambda / (2 * chirps_per_subframe * PRI), matching radar_scene.py.
+        """
        c = 299_792_458.0
        wavelength = c / self.center_freq_hz
-        return wavelength / (2.0 * self.n_doppler_bins * self.chirp_duration_s)
+        return wavelength / (2.0 * self.chirps_per_subframe * self.pri_s)

    @property
    def max_range_m(self) -> float:
@@ -334,7 +334,7 @@ class TargetSimulator(QObject):
            self._add_random_target()

    def _add_random_target(self):
-        range_m = random.uniform(5000, 40000)
+        range_m = random.uniform(50, 1400)
        azimuth = random.uniform(0, 360)
        velocity = random.uniform(-100, 100)
        elevation = random.uniform(-5, 45)
@@ -368,7 +368,7 @@ class TargetSimulator(QObject):

        for t in self._targets:
            new_range = t.range - t.velocity * 0.5
-            if new_range < 500 or new_range > 50000:
+            if new_range < 10 or new_range > 1536:
                continue  # target exits coverage — drop it

            new_vel = max(-150, min(150, t.velocity + random.uniform(-2, 2)))
@@ -0,0 +1,216 @@
+"""ADAR1000 vector-modulator ground-truth table and firmware parser.
+
+This module is a pure data + helpers library imported by the cross-layer
+test suite (`9_Firmware/tests/cross_layer/test_cross_layer_contract.py`,
+class `TestTier2Adar1000VmTableGroundTruth`). It has no CLI entry point
+and no side effects on import beyond the structural assertion on the
+table length.
+
+Ground-truth source
+-------------------
+The 128-entry `(I, Q)` byte pairs below are transcribed from the ADAR1000
+datasheet Rev. B, Tables 13-16, page 34 ("Phase Shifter Programming"),
+which is the primary normative reference. The same values appear in the
+Analog Devices Linux beamformer driver
+(`drivers/iio/beamformer/adar1000.c`, `adar1000_phase_values[]`) and were
+cross-checked against that driver as a secondary, independent
+transcription. The byte values are factual data (5-bit unsigned magnitude
+in bits[4:0], polarity bit at bit[5], bits[7:6] reserved zero); no
+copyrightable creative expression. Only the datasheet is the
+licensing-relevant source.
+
+PLFM_RADAR firmware indexing convention
+---------------------------------------
+`adarSetRxPhase` / `adarSetTxPhase` in
+`9_Firmware/9_1_Microcontroller/9_1_1_C_Cpp_Libraries/ADAR1000_Manager.cpp`
+write `VM_I[phase % 128]` and `VM_Q[phase % 128]` to the chip. Each index
+N corresponds to commanded beam phase `N * 360/128 = N * 2.8125 deg`. The
+ADI table is also on a uniform 2.8125 deg grid (verified by
+`check_uniform_2p8125_deg_step` below), so a 1:1 mapping is correct:
+PLFM index N == ADI table row N.
+"""
+
+from __future__ import annotations
+
+import re
+
+# ----------------------------------------------------------------------------
+# Ground truth: ADAR1000 datasheet Rev. B Tables 13-16 p.34
+# Each entry: (angle_int_deg, angle_frac_x10000, vm_byte_I, vm_byte_Q)
+# ----------------------------------------------------------------------------
+GROUND_TRUTH: list[tuple[int, int, int, int]] = [
+    (0, 0, 0x3F, 0x20), (2, 8125, 0x3F, 0x21), (5, 6250, 0x3F, 0x23),
+    (8, 4375, 0x3F, 0x24), (11, 2500, 0x3F, 0x26), (14, 625, 0x3E, 0x27),
+    (16, 8750, 0x3E, 0x28), (19, 6875, 0x3D, 0x2A), (22, 5000, 0x3D, 0x2B),
+    (25, 3125, 0x3C, 0x2D), (28, 1250, 0x3C, 0x2E), (30, 9375, 0x3B, 0x2F),
+    (33, 7500, 0x3A, 0x30), (36, 5625, 0x39, 0x31), (39, 3750, 0x38, 0x33),
+    (42, 1875, 0x37, 0x34), (45, 0, 0x36, 0x35), (47, 8125, 0x35, 0x36),
+    (50, 6250, 0x34, 0x37), (53, 4375, 0x33, 0x38), (56, 2500, 0x32, 0x38),
+    (59, 625, 0x30, 0x39), (61, 8750, 0x2F, 0x3A), (64, 6875, 0x2E, 0x3A),
+    (67, 5000, 0x2C, 0x3B), (70, 3125, 0x2B, 0x3C), (73, 1250, 0x2A, 0x3C),
+    (75, 9375, 0x28, 0x3C), (78, 7500, 0x27, 0x3D), (81, 5625, 0x25, 0x3D),
+    (84, 3750, 0x24, 0x3D), (87, 1875, 0x22, 0x3D), (90, 0, 0x21, 0x3D),
+    (92, 8125, 0x01, 0x3D), (95, 6250, 0x03, 0x3D), (98, 4375, 0x04, 0x3D),
+    (101, 2500, 0x06, 0x3D), (104, 625, 0x07, 0x3C), (106, 8750, 0x08, 0x3C),
+    (109, 6875, 0x0A, 0x3C), (112, 5000, 0x0B, 0x3B), (115, 3125, 0x0D, 0x3A),
+    (118, 1250, 0x0E, 0x3A), (120, 9375, 0x0F, 0x39), (123, 7500, 0x11, 0x38),
+    (126, 5625, 0x12, 0x38), (129, 3750, 0x13, 0x37), (132, 1875, 0x14, 0x36),
+    (135, 0, 0x16, 0x35), (137, 8125, 0x17, 0x34), (140, 6250, 0x18, 0x33),
+    (143, 4375, 0x19, 0x31), (146, 2500, 0x19, 0x30), (149, 625, 0x1A, 0x2F),
+    (151, 8750, 0x1B, 0x2E), (154, 6875, 0x1C, 0x2D), (157, 5000, 0x1C, 0x2B),
+    (160, 3125, 0x1D, 0x2A), (163, 1250, 0x1E, 0x28), (165, 9375, 0x1E, 0x27),
+    (168, 7500, 0x1E, 0x26), (171, 5625, 0x1F, 0x24), (174, 3750, 0x1F, 0x23),
+    (177, 1875, 0x1F, 0x21), (180, 0, 0x1F, 0x20), (182, 8125, 0x1F, 0x01),
+    (185, 6250, 0x1F, 0x03), (188, 4375, 0x1F, 0x04), (191, 2500, 0x1F, 0x06),
+    (194, 625, 0x1E, 0x07), (196, 8750, 0x1E, 0x08), (199, 6875, 0x1D, 0x0A),
+    (202, 5000, 0x1D, 0x0B), (205, 3125, 0x1C, 0x0D), (208, 1250, 0x1C, 0x0E),
+    (210, 9375, 0x1B, 0x0F), (213, 7500, 0x1A, 0x10), (216, 5625, 0x19, 0x11),
+    (219, 3750, 0x18, 0x13), (222, 1875, 0x17, 0x14), (225, 0, 0x16, 0x15),
+    (227, 8125, 0x15, 0x16), (230, 6250, 0x14, 0x17), (233, 4375, 0x13, 0x18),
+    (236, 2500, 0x12, 0x18), (239, 625, 0x10, 0x19), (241, 8750, 0x0F, 0x1A),
+    (244, 6875, 0x0E, 0x1A), (247, 5000, 0x0C, 0x1B), (250, 3125, 0x0B, 0x1C),
+    (253, 1250, 0x0A, 0x1C), (255, 9375, 0x08, 0x1C), (258, 7500, 0x07, 0x1D),
+    (261, 5625, 0x05, 0x1D), (264, 3750, 0x04, 0x1D), (267, 1875, 0x02, 0x1D),
+    (270, 0, 0x01, 0x1D), (272, 8125, 0x21, 0x1D), (275, 6250, 0x23, 0x1D),
+    (278, 4375, 0x24, 0x1D), (281, 2500, 0x26, 0x1D), (284, 625, 0x27, 0x1C),
+    (286, 8750, 0x28, 0x1C), (289, 6875, 0x2A, 0x1C), (292, 5000, 0x2B, 0x1B),
+    (295, 3125, 0x2D, 0x1A), (298, 1250, 0x2E, 0x1A), (300, 9375, 0x2F, 0x19),
+    (303, 7500, 0x31, 0x18), (306, 5625, 0x32, 0x18), (309, 3750, 0x33, 0x17),
+    (312, 1875, 0x34, 0x16), (315, 0, 0x36, 0x15), (317, 8125, 0x37, 0x14),
+    (320, 6250, 0x38, 0x13), (323, 4375, 0x39, 0x11), (326, 2500, 0x39, 0x10),
+    (329, 625, 0x3A, 0x0F), (331, 8750, 0x3B, 0x0E), (334, 6875, 0x3C, 0x0D),
+    (337, 5000, 0x3C, 0x0B), (340, 3125, 0x3D, 0x0A), (343, 1250, 0x3E, 0x08),
+    (345, 9375, 0x3E, 0x07), (348, 7500, 0x3E, 0x06), (351, 5625, 0x3F, 0x04),
+    (354, 3750, 0x3F, 0x03), (357, 1875, 0x3F, 0x01),
+]
+
+assert len(GROUND_TRUTH) == 128, f"GROUND_TRUTH must have 128 entries, has {len(GROUND_TRUTH)}"
+
+VM_I_REF: list[int] = [row[2] for row in GROUND_TRUTH]
+VM_Q_REF: list[int] = [row[3] for row in GROUND_TRUTH]
+
+
+# ----------------------------------------------------------------------------
+# Structural-invariant checks on the embedded ground-truth transcription.
+# These defend against typos during the copy-paste from the datasheet / ADI
+# driver. Each function returns a list of error strings (empty == pass) so
+# callers (the pytest class) can assert-on-empty with a useful message.
+# ----------------------------------------------------------------------------
+def check_byte_format(label: str, table: list[int]) -> list[str]:
+    """Each byte must have bits[7:6] == 0 (reserved)."""
+    errors = []
+    for i, byte in enumerate(table):
+        if byte & 0xC0:
+            errors.append(f"{label}[{i}]=0x{byte:02X}: reserved bits[7:6] non-zero")
+    return errors
+
+
+def check_uniform_2p8125_deg_step() -> list[str]:
+    """Angles must form a uniform 2.8125 deg grid: angle[N] == N * 2.8125."""
+    errors = []
+    for i, (deg_int, deg_frac, _, _) in enumerate(GROUND_TRUTH):
+        # angle in units of 1/10000 degree; 2.8125 deg = 28125/10000 exactly
+        angle_e4 = deg_int * 10000 + deg_frac
+        expected_e4 = i * 28125
+        if angle_e4 != expected_e4:
+            errors.append(
+                f"GROUND_TRUTH[{i}]: angle {deg_int}.{deg_frac:04d} deg "
+                f"(={angle_e4}/10000) != expected {expected_e4}/10000 "
+                f"(=i*2.8125)"
+            )
+    return errors
+
+
+def check_quadrant_symmetry() -> list[str]:
+    """Angle and angle+180 deg must have inverted polarity bits but identical
+    magnitudes. Index offset 64 corresponds to 180 deg on the 128-step grid.
+
+    Exemption: when magnitude is zero the polarity bit is physically
+    meaningless (sign of zero is undefined for the IQ phasor projection).
+    The datasheet uses POL=1 for both 0 and 180 deg Q components (both
+    encode Q=0). Skip the polarity assertion for zero-magnitude entries.
+    """
+    errors = []
+    POL = 0x20
+    MAG = 0x1F
+    for i in range(64):
+        j = i + 64
+        mag_i_a, mag_i_b = VM_I_REF[i] & MAG, VM_I_REF[j] & MAG
+        if mag_i_a != mag_i_b:
+            errors.append(
+                f"VM_I[{i}]=0x{VM_I_REF[i]:02X} vs VM_I[{j}]=0x{VM_I_REF[j]:02X}: "
+                f"180 deg pair has different magnitude"
+            )
+        if mag_i_a != 0 and (VM_I_REF[i] & POL) == (VM_I_REF[j] & POL):
+            errors.append(
+                f"VM_I[{i}]=0x{VM_I_REF[i]:02X} vs VM_I[{j}]=0x{VM_I_REF[j]:02X}: "
+                f"180 deg pair has same polarity (should be inverted, mag={mag_i_a})"
+            )
+        mag_q_a, mag_q_b = VM_Q_REF[i] & MAG, VM_Q_REF[j] & MAG
+        if mag_q_a != mag_q_b:
+            errors.append(
+                f"VM_Q[{i}]=0x{VM_Q_REF[i]:02X} vs VM_Q[{j}]=0x{VM_Q_REF[j]:02X}: "
+                f"180 deg pair has different magnitude"
+            )
+        if mag_q_a != 0 and (VM_Q_REF[i] & POL) == (VM_Q_REF[j] & POL):
+            errors.append(
+                f"VM_Q[{i}]=0x{VM_Q_REF[i]:02X} vs VM_Q[{j}]=0x{VM_Q_REF[j]:02X}: "
+                f"180 deg pair has same polarity (should be inverted, mag={mag_q_a})"
+            )
+    return errors
+
+
+def check_cardinal_points() -> list[str]:
+    """Spot-check cardinal phase points against datasheet expectations."""
+    errors = []
+    expectations = [
+        (0,  0x3F, 0x20, "0 deg: max +I, ~zero Q"),
+        (32, 0x21, 0x3D, "90 deg: ~zero I, max +Q"),
+        (64, 0x1F, 0x20, "180 deg: max -I, ~zero Q"),
+        (96, 0x01, 0x1D, "270 deg: ~zero I, max -Q"),
+    ]
+    for idx, exp_i, exp_q, desc in expectations:
+        if VM_I_REF[idx] != exp_i or VM_Q_REF[idx] != exp_q:
+            errors.append(
+                f"index {idx} ({desc}): expected (0x{exp_i:02X}, 0x{exp_q:02X}), "
+                f"got (0x{VM_I_REF[idx]:02X}, 0x{VM_Q_REF[idx]:02X})"
+            )
+    return errors
+
+
+# ----------------------------------------------------------------------------
+# Parse VM_I[] / VM_Q[] from firmware C++ source.
+# ----------------------------------------------------------------------------
+ARRAY_RE = re.compile(
+    r"const\s+uint8_t\s+ADAR1000Manager::(?P<name>VM_I|VM_Q|VM_GAIN)\s*"
+    r"\[\s*128\s*\]\s*=\s*\{(?P<body>[^}]*)\}\s*;",
+    re.DOTALL,
+)
+HEX_RE = re.compile(r"0[xX][0-9a-fA-F]{1,2}")
+
+
+def parse_array(source: str, name: str) -> list[int] | None:
+    """Extract a 128-entry uint8_t array from C++ source by name.
+
+    Returns None if the array is not found. Returns a list (possibly shorter
+    than 128) of the parsed bytes if found; caller is responsible for length
+    validation.
+
+    LIMITATION (intentional, see PR fix/adar1000-vm-tables review finding #2):
+    ARRAY_RE uses `[^}]*` for the body, which terminates at the first `}`.
+    This is sufficient for the *flat* `const uint8_t NAME[128] = { ... };`
+    declarations VM_I/VM_Q use today, but it would mis-parse if the array
+    body ever contained nested braces (e.g. designated initialisers, struct
+    aggregates, or macro-expansions producing braces). If the firmware ever
+    needs such a form for the VM tables, replace ARRAY_RE with a balanced
+    brace-counting parser. Until then, the current regex is preferred for
+    its simplicity and the round-trip tests will catch any silent breakage.
+    """
+    for m in ARRAY_RE.finditer(source):
+        if m.group("name") != name:
+            continue
+        body = m.group("body")
+        body = re.sub(r"//[^\n]*", "", body)
+        body = re.sub(r"/\*.*?\*/", "", body, flags=re.DOTALL)
+        return [int(tok, 16) for tok in HEX_RE.findall(body)]
+    return None
@@ -188,7 +188,7 @@ def parse_python_data_packet_fields(filepath: Path | None = None) -> list[DataPa
            width_bits=size * 8
        ))

-    # Match detection = raw[9] & 0x01
+    # Match detection = raw[9] & 0x01  (direct access)
    for m in re.finditer(r'(\w+)\s*=\s*raw\[(\d+)\]\s*&\s*(0x[0-9a-fA-F]+|\d+)', body):
        name = m.group(1)
        offset = int(m.group(2))
@@ -196,6 +196,24 @@ def parse_python_data_packet_fields(filepath: Path | None = None) -> list[DataPa
            name=name, byte_start=offset, byte_end=offset, width_bits=1
        ))

+    # Match intermediate variable pattern: var = raw[N], then field = var & MASK
+    for m in re.finditer(r'(\w+)\s*=\s*raw\[(\d+)\]', body):
+        var_name = m.group(1)
+        offset = int(m.group(2))
+        # Find fields derived from this intermediate variable
+        for m2 in re.finditer(
+            rf'(\w+)\s*=\s*(?:\({var_name}\s*>>\s*\d+\)\s*&|{var_name}\s*&)\s*'
+            r'(0x[0-9a-fA-F]+|\d+)',
+            body,
+        ):
+            name = m2.group(1)
+            # Skip if already captured by direct raw[] access pattern
+            if not any(f.name == name for f in fields):
+                fields.append(DataPacketField(
+                    name=name, byte_start=offset, byte_end=offset,
+                    width_bits=1
+                ))
+
    fields.sort(key=lambda f: f.byte_start)
    return fields

@@ -497,6 +515,7 @@ def count_concat_bits(concat_expr: str, port_widths: dict[str, int]) -> ConcatWi
            # Unknown width — flag it
            fragments.append((part, -1))
            total = -1  # Can't compute
+            break

    return ConcatWidth(
        total_bits=total,
@@ -583,12 +602,28 @@ def parse_verilog_data_mux(

    for m in re.finditer(
        r"5'd(\d+)\s*:\s*data_pkt_byte\s*=\s*(.+?);",
-        mux_body
+        mux_body, re.DOTALL
    ):
        idx = int(m.group(1))
        expr = m.group(2).strip()
        entries.append((idx, expr))

+    # Helper: extract the dominant signal name from a mux expression.
+    # Handles direct refs like ``range_profile_cap[31:24]``, ternaries
+    # like ``stream_doppler_en ? doppler_real_cap[15:8] : 8'd0``, and
+    # concat-ternaries like ``stream_cfar_en ? {…, cfar_detection_cap} : …``.
+    def _extract_signal(expr: str) -> str | None:
+        # If it's a ternary, use the true-branch to find the data signal
+        tern = re.match(r'\w+\s*\?\s*(.+?)\s*:\s*.+', expr, re.DOTALL)
+        target = tern.group(1) if tern else expr
+        # Look for a known data signal (xxx_cap pattern or cfar_detection_cap)
+        cap_match = re.search(r'(\w+_cap)\b', target)
+        if cap_match:
+            return cap_match.group(1)
+        # Fall back to first identifier before a bit-select
+        sig_match = re.match(r'(\w+?)(?:\[|$)', target)
+        return sig_match.group(1) if sig_match else None
+
    # Group consecutive bytes by signal root name
    fields: list[DataPacketField] = []
    i = 0
@@ -598,22 +633,21 @@ def parse_verilog_data_mux(
            i += 1
            continue

-        # Extract signal name (e.g., range_profile_cap from range_profile_cap[31:24])
-        sig_match = re.match(r'(\w+?)(?:\[|$)', expr)
-        if not sig_match:
+        signal = _extract_signal(expr)
+        if not signal:
            i += 1
            continue

-        signal = sig_match.group(1)
        start_byte = idx
        end_byte = idx

        # Find consecutive bytes of the same signal
        j = i + 1
        while j < len(entries):
-            next_idx, next_expr = entries[j]
-            if next_expr.startswith(signal):
-                end_byte = next_idx
+            _next_idx, next_expr = entries[j]
+            next_sig = _extract_signal(next_expr)
+            if next_sig == signal:
+                end_byte = _next_idx
                j += 1
            else:
                break
@@ -620,8 +620,10 @@ module tb_cross_layer_ft2232h;
              "Data pkt: byte 7 = 0x56 (doppler_imag MSB)");
        check(captured_bytes[8] === 8'h78,
              "Data pkt: byte 8 = 0x78 (doppler_imag LSB)");
-        check(captured_bytes[9] === 8'h01,
-              "Data pkt: byte 9 = 0x01 (cfar_detection=1)");
+        // Byte 9 = {frame_start, 6'b0, cfar_detection}
+        // After reset sample_counter==0, so frame_start=1 → 0x81
+        check(captured_bytes[9] === 8'h81,
+              "Data pkt: byte 9 = 0x81 (frame_start=1, cfar_detection=1)");
        check(captured_bytes[10] === 8'h55,
              "Data pkt: byte 10 = 0x55 (footer)");

@@ -26,11 +26,14 @@ layers agree (because both could be wrong).

 from __future__ import annotations

+import ast
 import os
+import re
 import struct
 import subprocess
 import tempfile
 from pathlib import Path
+from typing import ClassVar

 import pytest

@@ -40,6 +43,7 @@ import sys
 THIS_DIR = Path(__file__).resolve().parent
 sys.path.insert(0, str(THIS_DIR))
 import contract_parser as cp  # noqa: E402
+import adar1000_vm_reference as adar_vm  # noqa: E402

 # Also add the GUI dir to import radar_protocol
 sys.path.insert(0, str(cp.GUI_DIR))
@@ -49,8 +53,8 @@ sys.path.insert(0, str(cp.GUI_DIR))
 # Helpers
 # ===================================================================

-IVERILOG = os.environ.get("IVERILOG", "/opt/homebrew/bin/iverilog")
-VVP = os.environ.get("VVP", "/opt/homebrew/bin/vvp")
+IVERILOG = os.environ.get("IVERILOG", "iverilog")
+VVP = os.environ.get("VVP", "vvp")
 CXX = os.environ.get("CXX", "c++")

 # Check tool availability for conditional skipping
@@ -61,6 +65,92 @@ _has_cxx = subprocess.run(
    [CXX, "--version"], capture_output=True
 ).returncode == 0

+# In CI, missing tools must be a hard failure — never silently skip.
+_in_ci = os.environ.get("GITHUB_ACTIONS") == "true"
+if _in_ci:
+    if not _has_iverilog:
+        raise RuntimeError(
+            "iverilog is required in CI but was not found. "
+            "Ensure 'apt-get install iverilog' ran and IVERILOG/VVP are on PATH."
+        )
+    if not _has_cxx:
+        raise RuntimeError(
+            "C++ compiler is required in CI but was not found. "
+            "Ensure build-essential is installed."
+        )
+
+
+def _strip_cxx_comments_and_strings(src: str) -> str:
+    """Return src with all C/C++ comments and string/char literals removed.
+
+    Tokenising state machine with four states:
+      * CODE              — default; watches for `"`, `'`, `//`, `/*`
+      * STRING ("...")    — handles `\\"` and `\\\\` escapes
+      * CHAR   ('...')    — handles `\\'` and `\\\\` escapes
+      * LINE_COMMENT      — until next `\\n`
+      * BLOCK_COMMENT     — until next `*/`
+
+    Used by test_vm_gain_table_is_not_reintroduced to ensure the substring
+    "VM_GAIN" appearing only inside an explanatory comment or a string
+    literal does NOT count as code reintroduction. We replace stripped
+    regions with a single space so token boundaries (and line counts, by
+    approximation — newlines preserved) are not collapsed.
+    """
+    out: list[str] = []
+    i = 0
+    n = len(src)
+    CODE, STRING, CHAR, LINE_C, BLOCK_C = 0, 1, 2, 3, 4
+    state = CODE
+    while i < n:
+        c = src[i]
+        nxt = src[i + 1] if i + 1 < n else ""
+        if state == CODE:
+            if c == "/" and nxt == "/":
+                state = LINE_C
+                i += 2
+            elif c == "/" and nxt == "*":
+                state = BLOCK_C
+                i += 2
+            elif c == '"':
+                state = STRING
+                i += 1
+            elif c == "'":
+                state = CHAR
+                i += 1
+            else:
+                out.append(c)
+                i += 1
+        elif state == STRING:
+            if c == "\\" and i + 1 < n:
+                i += 2  # skip escape pair (handles \" and \\)
+            elif c == '"':
+                state = CODE
+                i += 1
+            else:
+                i += 1
+        elif state == CHAR:
+            if c == "\\" and i + 1 < n:
+                i += 2
+            elif c == "'":
+                state = CODE
+                i += 1
+            else:
+                i += 1
+        elif state == LINE_C:
+            if c == "\n":
+                out.append("\n")  # preserve line numbering
+                state = CODE
+            i += 1
+        elif state == BLOCK_C:
+            if c == "*" and nxt == "/":
+                state = CODE
+                i += 2
+            else:
+                if c == "\n":
+                    out.append("\n")
+                i += 1
+    return "".join(out)
+

 def _parse_hex_results(text: str) -> list[dict[str, str]]:
    """Parse space-separated hex lines from TB output files."""
@@ -355,6 +445,602 @@ class TestTier1ResetDefaults:
            )


+class TestTier1AgcCrossLayerInvariant:
+    """
+    Verify AGC enable/disable is consistent across FPGA, MCU, and GUI layers.
+
+    System-level invariant: the FPGA register host_agc_enable is the single
+    source of truth for AGC state. It propagates to MCU via DIG_6 GPIO and
+    to GUI via status word 4 bit[11]. At boot, all layers must agree AGC=OFF.
+    At runtime, the MCU must read DIG_6 every frame to sync its outer-loop AGC.
+    """
+
+    def test_fpga_dig6_drives_agc_enable(self):
+        """FPGA must drive gpio_dig6 from host_agc_enable, NOT tied low."""
+        rtl = (cp.FPGA_DIR / "radar_system_top.v").read_text()
+        # Must find: assign gpio_dig6 = host_agc_enable;
+        assert re.search(
+            r'assign\s+gpio_dig6\s*=\s*host_agc_enable\s*;', rtl
+        ), "gpio_dig6 must be driven by host_agc_enable (not tied low)"
+        # Must NOT have the old tied-low pattern
+        assert not re.search(
+            r"assign\s+gpio_dig6\s*=\s*1'b0\s*;", rtl
+        ), "gpio_dig6 must NOT be tied low — it carries AGC enable"
+
+    def test_fpga_agc_enable_boot_default_off(self):
+        """FPGA host_agc_enable must reset to 0 (AGC off at boot)."""
+        v_defaults = cp.parse_verilog_reset_defaults()
+        assert "host_agc_enable" in v_defaults, (
+            "host_agc_enable not found in reset block"
+        )
+        assert v_defaults["host_agc_enable"] == 0, (
+            f"host_agc_enable reset default is {v_defaults['host_agc_enable']}, "
+            "expected 0 (AGC off at boot)"
+        )
+
+    def test_mcu_agc_constructor_default_off(self):
+        """MCU ADAR1000_AGC constructor must default enabled=false."""
+        agc_cpp = (cp.MCU_LIB_DIR / "ADAR1000_AGC.cpp").read_text()
+        # The constructor initializer list must have enabled(false)
+        assert re.search(
+            r'enabled\s*\(\s*false\s*\)', agc_cpp
+        ), "ADAR1000_AGC constructor must initialize enabled(false)"
+        assert not re.search(
+            r'enabled\s*\(\s*true\s*\)', agc_cpp
+        ), "ADAR1000_AGC constructor must NOT initialize enabled(true)"
+
+    def test_mcu_reads_dig6_before_agc_gate(self):
+        """MCU main loop must read DIG_6 GPIO to sync outerAgc.enabled."""
+        main_cpp = (cp.MCU_CODE_DIR / "main.cpp").read_text()
+        # DIG_6 must be read via HAL_GPIO_ReadPin
+        assert re.search(
+            r'HAL_GPIO_ReadPin\s*\(\s*FPGA_DIG6', main_cpp,
+        ), "main.cpp must read DIG_6 GPIO via HAL_GPIO_ReadPin"
+        # outerAgc.enabled must be assigned from the DIG_6 reading
+        # (may be indirect via debounce variable like dig6_now)
+        assert re.search(
+            r'outerAgc\.enabled\s*=', main_cpp,
+        ), "main.cpp must assign outerAgc.enabled from DIG_6 state"
+
+    def test_boot_invariant_all_layers_agc_off(self):
+        """
+        At boot, all three layers must agree: AGC is OFF.
+        - FPGA: host_agc_enable resets to 0 -> DIG_6 low
+        - MCU: ADAR1000_AGC.enabled defaults to false
+        - GUI: reads status word 4 bit[11] = 0 -> reports MANUAL
+        """
+        # FPGA
+        v_defaults = cp.parse_verilog_reset_defaults()
+        assert v_defaults.get("host_agc_enable") == 0
+
+        # MCU
+        agc_cpp = (cp.MCU_LIB_DIR / "ADAR1000_AGC.cpp").read_text()
+        assert re.search(r'enabled\s*\(\s*false\s*\)', agc_cpp)
+
+        # GUI: status word 4 bit[11] is host_agc_enable, which resets to 0.
+        # Verify the GUI parses bit[11] of status word 4 as the AGC flag.
+        gui_py = (cp.GUI_DIR / "radar_protocol.py").read_text()
+        assert re.search(
+            r'words\[4\].*>>\s*11|status_words\[4\].*>>\s*11',
+            gui_py,
+        ), "GUI must parse AGC status from words[4] bit[11]"
+
+    def test_status_word4_agc_bit_matches_dig6_source(self):
+        """
+        Status word 4 bit[11] and DIG_6 must both derive from host_agc_enable.
+        This guarantees the GUI status display can never lie about MCU AGC state.
+        """
+        rtl = (cp.FPGA_DIR / "radar_system_top.v").read_text()
+
+        # DIG_6 driven by host_agc_enable
+        assert re.search(
+            r'assign\s+gpio_dig6\s*=\s*host_agc_enable\s*;', rtl
+        )
+
+        # Status word 4 must contain host_agc_enable (may be named
+        # status_agc_enable at the USB interface port boundary).
+        # Also verify the top-level wiring connects them.
+        usb_ft2232h = (cp.FPGA_DIR / "usb_data_interface_ft2232h.v").read_text()
+        usb_ft601 = (cp.FPGA_DIR / "usb_data_interface.v").read_text()
+
+        # USB interfaces use the port name status_agc_enable
+        found_in_ft2232h = "status_agc_enable" in usb_ft2232h
+        found_in_ft601 = "status_agc_enable" in usb_ft601
+
+        assert found_in_ft2232h or found_in_ft601, (
+            "status_agc_enable must appear in at least one USB interface's "
+            "status word to guarantee GUI status matches DIG_6"
+        )
+
+        # Verify top-level wiring: status_agc_enable port is connected
+        # to host_agc_enable (same signal that drives DIG_6)
+        assert re.search(
+            r'\.status_agc_enable\s*\(\s*host_agc_enable\s*\)', rtl
+        ), (
+            "Top-level must wire .status_agc_enable(host_agc_enable) "
+            "so status word and DIG_6 derive from the same signal"
+        )
+
+    def test_mcu_dig6_debounce_guards_enable_assignment(self):
+        """
+        MCU must apply a 2-frame confirmation debounce before mutating
+        outerAgc.enabled from DIG_6 reads. A naive assignment straight from
+        the latest GPIO sample would let a single-cycle glitch flip the AGC
+        state for one frame — defeating the debounce claim in the PR body.
+        """
+        main_cpp = (cp.MCU_CODE_DIR / "main.cpp").read_text()
+
+        # (1) Current-frame DIG_6 sample must be captured in a local variable
+        # so it can be compared against the previous-frame value.
+        now_match = re.search(
+            r'(bool|int|uint8_t)\s+(\w*dig6\w*)\s*=\s*[^;]*?'
+            r'HAL_GPIO_ReadPin\s*\(\s*FPGA_DIG6[^;]*;',
+            main_cpp,
+            re.DOTALL,
+        )
+        assert now_match, (
+            "DIG_6 read must be stored in a local variable (e.g. `dig6_now`) "
+            "so the current sample can be compared against the previous frame"
+        )
+        now_var = now_match.group(2)
+
+        # (2) Previous-frame state must persist across iterations via static
+        # storage, and must default to false (matches FPGA boot: AGC off).
+        prev_match = re.search(
+            r'static\s+(bool|int|uint8_t)\s+(\w*dig6\w*)\s*=\s*(false|0)\s*;',
+            main_cpp,
+        )
+        assert prev_match, (
+            "A static previous-frame variable (e.g. "
+            "`static bool dig6_prev = false;`) must exist, initialized to "
+            "false so the debounce starts in sync with the FPGA boot default"
+        )
+        prev_var = prev_match.group(2)
+        assert prev_var != now_var, (
+            f"Current and previous DIG_6 variables must be distinct "
+            f"(both are '{now_var}')"
+        )
+
+        # (3) outerAgc.enabled assignment must be gated by now == prev.
+        guarded_assign = re.search(
+            rf'if\s*\(\s*{now_var}\s*==\s*{prev_var}\s*\)\s*\{{[^}}]*?'
+            rf'outerAgc\.enabled\s*=\s*{now_var}\s*;',
+            main_cpp,
+            re.DOTALL,
+        )
+        assert guarded_assign, (
+            f"`outerAgc.enabled = {now_var};` must be inside "
+            f"`if ({now_var} == {prev_var}) {{ ... }}` — the confirmation "
+            "guard that absorbs single-sample GPIO glitches. A naive "
+            "assignment without this guard reintroduces the glitch bug."
+        )
+
+        # (4) Previous-frame variable must advance each frame.
+        prev_update = re.search(
+            rf'{prev_var}\s*=\s*{now_var}\s*;',
+            main_cpp,
+        )
+        assert prev_update, (
+            f"`{prev_var} = {now_var};` must run each frame so the "
+            "debounce window slides forward; without it the guard is "
+            "stuck and enable changes never confirm"
+        )
+
+
+# ===================================================================
+# ADAR1000 channel→register round-trip invariant (issue #90)
+# ===================================================================
+#
+# Ground-truth invariant crossing three system layers:
+#   Chip (datasheet) -> Driver (MCU helpers) -> Application (callers).
+#
+# For every logical element ch in {0,1,2,3} (hardware channels CH1..CH4),
+# the round-trip
+#     caller_expr(ch) --> helper_offset(channel) * stride --> base + off
+# must land on the physical register REG_CH{ch+1}_* defined in the ADI
+# ADAR1000 register map parsed from ADAR1000_Manager.h.
+#
+# Catches:
+#   * #90 channel rotation regardless of which side is fixed (caller OR helper).
+#   * Wrong stride (e.g. phase written with stride 1 instead of 2).
+#   * Bad mask (e.g. `channel & 0x07`, `channel & 0x01`).
+#   * Wrong base register in a helper.
+#   * New setter added with mismatched convention.
+#   * Caller moved to a file the test no longer scans (fails loudly).
+#
+# Cannot be defeated by:
+#   * Renaming/refactoring helper layout: the setter coverage test
+#     (`test_helper_sites_exist_for_all_setters`) catches missing parse.
+#   * Changing 0x03 to 3 or adding a named constant: the offset is
+#     evaluated symbolically via AST, not matched by regex.
+
+
+def _parse_adar_register_map(header_text):
+    """Extract `#define REG_CHn_(RX|TX)_(GAIN|PHS_I|PHS_Q)` values."""
+    regs = {}
+    for m in re.finditer(
+        r"^#define\s+(REG_CH[1-4]_(?:RX|TX)_(?:GAIN|PHS_I|PHS_Q))\s+(0x[0-9A-Fa-f]+)",
+        header_text,
+        re.MULTILINE,
+    ):
+        regs[m.group(1)] = int(m.group(2), 16)
+    return regs
+
+
+def _safe_eval_int_expr(expr, **variables):
+    """
+    Evaluate a small integer expression with +, -, *, &, |, ^, ~, <<, >>.
+    Python's & / | / ^ / ~ / << / >> have the same semantics as C for the
+    operand widths we care about here (uint8_t after the mask makes the
+    result fit in 0..3). No floating point, no function calls, no names
+    outside ``variables``.
+
+    SECURITY: ``expr`` MUST come from a trusted source -- specifically,
+    C/C++ source text under version control in this repository (e.g.
+    arguments parsed out of ``main.cpp``/``ADAR1000_AGC.cpp``).  Although
+    the AST whitelist below rejects function calls, attribute access,
+    subscripts, and any name not in ``variables``, ``eval`` is still
+    invoked on the compiled tree.  Do NOT pass user-supplied / network /
+    GUI input here.
+    """
+    tree = ast.parse(expr, mode="eval")
+    allowed = (
+        ast.Expression, ast.BinOp, ast.UnaryOp, ast.Constant,
+        ast.Name, ast.Load,
+        ast.Add, ast.Sub, ast.Mult, ast.Mod, ast.FloorDiv,
+        ast.BitAnd, ast.BitOr, ast.BitXor,
+        ast.USub, ast.UAdd, ast.Invert,
+        ast.LShift, ast.RShift,
+    )
+    for node in ast.walk(tree):
+        if not isinstance(node, allowed):
+            raise ValueError(
+                f"disallowed AST node {type(node).__name__!s} in `{expr}`"
+            )
+    return eval(
+        compile(tree, "<expr>", "eval"),
+        {"__builtins__": {}},
+        variables,
+    )
+
+
+def _extract_adar_helper_sites(manager_cpp, setter_names):
+    """
+    For each setter, locate the body of ``void ADAR1000Manager::<setter>``
+    and return a list of (setter, base_register, offset_expr_c, stride)
+    for every ``REG_CHn_XXX + <expr>`` memory-address assignment.
+    """
+    sites = []
+    for setter in setter_names:
+        m = re.search(
+            rf"void\s+ADAR1000Manager::{setter}\s*\([^)]*\)\s*\{{(.+?)^\}}",
+            manager_cpp,
+            re.MULTILINE | re.DOTALL,
+        )
+        if not m:
+            continue
+        body = m.group(1)
+        for access in re.finditer(
+            r"=\s*(REG_CH[1-4]_(?:RX|TX)_(?:GAIN|PHS_I|PHS_Q))\s*\+\s*([^;]+);",
+            body,
+        ):
+            base = access.group(1)
+            rhs = access.group(2).strip()
+            # Trailing `* <integer>` = stride multiplier (2 for phase I/Q).
+            stride_match = re.match(r"(.+?)\s*\*\s*(\d+)\s*$", rhs)
+            if stride_match:
+                offset_expr = stride_match.group(1).strip()
+                stride = int(stride_match.group(2))
+            else:
+                offset_expr = rhs
+                stride = 1
+            sites.append((setter, base, offset_expr, stride))
+    return sites
+
+
+# Method-definition line pattern: `[qualifier...] <ret-type> <Class>::<setter>(`
+# Covers: plain `void X::f(`, `inline void X::f(`, `static bool X::f(`, etc.
+_DEFN_RE = re.compile(
+    r"^\s*(?:inline\s+|static\s+|virtual\s+|constexpr\s+|explicit\s+)*"
+    r"(?:void|bool|uint\w+|int\w*|auto)\s+\S+::\w+\s*\("
+)
+
+
+def _extract_adar_caller_sites(sources, setter):
+    """
+    Find every call ``<obj>.<setter>(dev, <channel_expr>, ...)`` across
+    ``sources = [(filename, text), ...]``. Returns (filename, line_no,
+    channel_expr) for each. Skips function declarations/definitions.
+
+    Arg list up to matching `)`: restricted to a single line. All existing
+    call sites fit on one line; a future multi-line refactor would drop
+    callers from the scan, which the round-trip test surfaces loudly via
+    `assert callers` (rather than silently missing a site).
+    """
+    out = []
+    call_re = re.compile(rf"\b{setter}\s*\(([^;]*?)\)\s*;")
+    for filename, text in sources:
+        for line_no, line in enumerate(text.splitlines(), start=1):
+            # Skip method definition / declaration lines.
+            if _DEFN_RE.match(line):
+                continue
+            cm = call_re.search(line)
+            if not cm:
+                continue
+            args = _split_top_level_commas(cm.group(1))
+            if len(args) < 2:
+                continue
+            channel_expr = args[1].strip()
+            out.append((filename, line_no, channel_expr))
+    return out
+
+
+def _split_top_level_commas(text):
+    """Split on commas that sit at paren-depth 0 (ignores nested calls)."""
+    parts, depth, cur = [], 0, []
+    for ch in text:
+        if ch == "(":
+            depth += 1
+            cur.append(ch)
+        elif ch == ")":
+            depth -= 1
+            cur.append(ch)
+        elif ch == "," and depth == 0:
+            parts.append("".join(cur))
+            cur = []
+        else:
+            cur.append(ch)
+    if cur:
+        parts.append("".join(cur))
+    return parts
+
+
+class TestTier1Adar1000ChannelRegisterRoundTrip:
+    """
+    Cross-layer round-trip: caller channel expr -> helper offset formula
+    -> physical register address must equal REG_CH{ch+1}_* for every
+    caller and every ch in {0,1,2,3}.
+
+    See module-level block comment above and upstream issue #90.
+    """
+
+    _SETTERS = (
+        "adarSetRxPhase",
+        "adarSetTxPhase",
+        "adarSetRxVgaGain",
+        "adarSetTxVgaGain",
+    )
+
+    # Register base -> stride override. Parsed values of stride are
+    # trusted; this table is the independent ground truth for cross-check.
+    _EXPECTED_STRIDE: ClassVar[dict[str, int]] = {
+        "REG_CH1_RX_GAIN": 1,
+        "REG_CH1_TX_GAIN": 1,
+        "REG_CH1_RX_PHS_I": 2,
+        "REG_CH1_RX_PHS_Q": 2,
+        "REG_CH1_TX_PHS_I": 2,
+        "REG_CH1_TX_PHS_Q": 2,
+    }
+
+    @classmethod
+    def setup_class(cls):
+        cls.header_txt = (cp.MCU_LIB_DIR / "ADAR1000_Manager.h").read_text()
+        cls.manager_txt = (cp.MCU_LIB_DIR / "ADAR1000_Manager.cpp").read_text()
+        cls.reg_map = _parse_adar_register_map(cls.header_txt)
+        cls.helper_sites = _extract_adar_helper_sites(
+            cls.manager_txt, cls._SETTERS,
+        )
+        # Auto-discover every C++ TU under the MCU tree so a new caller
+        # added to e.g. a future ``ADAR1000_Calibration.cpp`` cannot
+        # silently escape the round-trip check (issue #90 reviewer note).
+        # Exclude any path containing a ``tests`` segment so this test
+        # does not parse its own fixtures.  The resulting list is
+        # deterministic (sorted) for reproducible parametrization.
+        scanned = []
+        seen = set()
+        for root in (cp.MCU_LIB_DIR, cp.MCU_CODE_DIR):
+            for path in sorted(root.rglob("*.cpp")):
+                if "tests" in path.parts:
+                    continue
+                if path in seen:
+                    continue
+                seen.add(path)
+                scanned.append((path.name, path.read_text()))
+        cls.sources = scanned
+        # Sanity: the two TUs known to call ADAR1000 setters at the time
+        # of issue #90 must be in scope.  If a future refactor renames or
+        # moves them this assert fires loudly rather than silently
+        # passing an empty round-trip.
+        scanned_names = {n for (n, _) in scanned}
+        for required in ("ADAR1000_AGC.cpp", "main.cpp", "ADAR1000_Manager.cpp"):
+            assert required in scanned_names, (
+                f"Auto-discovery missed `{required}`; check MCU_LIB_DIR / "
+                f"MCU_CODE_DIR roots in contract_parser.py."
+            )
+
+    # ---------- Tier A: chip ground truth ----------------------------
+
+    def test_register_map_gain_stride_is_one_per_channel(self):
+        """Datasheet invariant: RX/TX VGA gain registers are 1 byte apart."""
+        for kind in ("RX_GAIN", "TX_GAIN"):
+            for n in range(1, 4):
+                delta = (
+                    self.reg_map[f"REG_CH{n+1}_{kind}"]
+                    - self.reg_map[f"REG_CH{n}_{kind}"]
+                )
+                assert delta == 1, (
+                    f"ADAR1000 register map invariant broken: "
+                    f"REG_CH{n+1}_{kind} - REG_CH{n}_{kind} = {delta}, "
+                    f"datasheet says 1. Either the header was mis-edited "
+                    f"or ADI released a part with a different map."
+                )
+
+    def test_register_map_phase_stride_is_two_per_channel(self):
+        """Datasheet invariant: phase I/Q pairs occupy 2 bytes per channel."""
+        for kind in ("RX_PHS_I", "RX_PHS_Q", "TX_PHS_I", "TX_PHS_Q"):
+            for n in range(1, 4):
+                delta = (
+                    self.reg_map[f"REG_CH{n+1}_{kind}"]
+                    - self.reg_map[f"REG_CH{n}_{kind}"]
+                )
+                assert delta == 2, (
+                    f"ADAR1000 register map invariant broken: "
+                    f"REG_CH{n+1}_{kind} - REG_CH{n}_{kind} = {delta}, "
+                    f"datasheet says 2."
+                )
+
+    # ---------- Tier B: driver parses cleanly -------------------------
+
+    def test_helper_sites_exist_for_all_setters(self):
+        """Every channel-indexed setter must parse at least one register access."""
+        found = {s for (s, _, _, _) in self.helper_sites}
+        missing = set(self._SETTERS) - found
+        assert not missing, (
+            f"Helper parse failed for: {sorted(missing)}. "
+            f"Either a setter was renamed (update _SETTERS), moved out of "
+            f"ADAR1000_Manager.cpp (extend scan scope), or the register-"
+            f"access form changed beyond `REG_CHn_XXX + <expr>`. "
+            f"DO NOT weaken this test without reviewing issue #90."
+        )
+
+    def test_helper_parsed_stride_matches_datasheet(self):
+        """Parsed helper strides must match the datasheet register spacing."""
+        for setter, base, offset_expr, stride in self.helper_sites:
+            expected = self._EXPECTED_STRIDE.get(base)
+            assert expected is not None, (
+                f"{setter} writes to unrecognised base `{base}`. "
+                f"If ADI added a new channel-indexed register block, "
+                f"extend _EXPECTED_STRIDE with its datasheet stride."
+            )
+            assert stride == expected, (
+                f"{setter} helper uses stride {stride} for `{base}` "
+                f"(`{offset_expr} * {stride}`), datasheet says {expected}. "
+                f"Writes will overlap or skip channels."
+            )
+
+    # ---------- Tier C: round-trip to physical register ---------------
+
+    def test_all_callers_pass_one_based_channel(self):
+        """
+        INVARIANT: every caller's channel argument must, for ch in
+        {0,1,2,3}, evaluate to a 1-based ADI channel index in {1,2,3,4}.
+
+        The bug fixed in #90 was that helpers used ``channel & 0x03``
+        directly, so a caller passing bare ``ch`` (0..3) appeared to
+        work for ch=0..2 and silently aliased ch=3 onto CH4-then-CH1.
+        After the fix, helpers do ``(channel - 1) & 0x03`` and reject
+        ``channel < 1 || channel > 4``.  A future caller written as
+        ``adarSetRxPhase(dev, ch, ...)`` (bare 0-based) or
+        ``adarSetRxPhase(dev, 0, ...)`` (literal 0) would silently be
+        dropped by the bounds-check at runtime; this test catches it at
+        CI time instead.
+
+        The check intentionally lives one tier above the round-trip test
+        so the failure message points the reader at the API contract
+        (1-based per ADI datasheet & ADAR1000_AGC.cpp:76) rather than at
+        a register-arithmetic mismatch.
+        """
+        offenders = []
+        for setter in self._SETTERS:
+            callers = _extract_adar_caller_sites(self.sources, setter)
+            for filename, line_no, ch_expr in callers:
+                for ch in range(4):
+                    try:
+                        channel_val = _safe_eval_int_expr(ch_expr, ch=ch)
+                    except (NameError, KeyError, ValueError) as e:
+                        offenders.append(
+                            f"  - {filename}:{line_no} {setter}("
+                            f"…, `{ch_expr}`, …) -- ch={ch}: "
+                            f"unparseable ({e})"
+                        )
+                        continue
+                    if channel_val not in (1, 2, 3, 4):
+                        offenders.append(
+                            f"  - {filename}:{line_no} {setter}("
+                            f"…, `{ch_expr}`, …) -- ch={ch}: "
+                            f"channel={channel_val}, expected 1..4"
+                        )
+        assert not offenders, (
+            "ADAR1000 1-based channel API contract violated. The fix "
+            "for issue #90 requires every caller to pass channel in "
+            "{1,2,3,4} (CH1..CH4 per ADI datasheet). Bare 0-based ch "
+            "or a literal 0 will be silently dropped by the helper's "
+            "bounds check.  Offenders:\n" + "\n".join(offenders)
+        )
+
+    @pytest.mark.parametrize(
+        "setter",
+        [
+            "adarSetRxPhase",
+            "adarSetTxPhase",
+            "adarSetRxVgaGain",
+            "adarSetTxVgaGain",
+        ],
+    )
+    def test_round_trip_lands_on_intended_physical_channel(self, setter):
+        """
+        INVARIANT: for every caller of ``<setter>`` and every logical ch
+        in {0,1,2,3}, the effective register address equals
+        REG_CH{ch+1}_*. Catches #90 regardless of fix direction.
+        """
+        callers = _extract_adar_caller_sites(self.sources, setter)
+        assert callers, (
+            f"No callers of `{setter}` found. Either the test scope is "
+            f"incomplete (extend `setup_class.sources`) or the symbol was "
+            f"inlined/removed. A blind test is a dangerous test — "
+            f"investigate before weakening."
+        )
+        helpers = [
+            (b, e, s) for (nm, b, e, s) in self.helper_sites if nm == setter
+        ]
+        assert helpers, f"helper body for `{setter}` not parseable"
+
+        errors = []
+        for filename, line_no, ch_expr in callers:
+            for ch in range(4):
+                try:
+                    channel_val = _safe_eval_int_expr(ch_expr, ch=ch)
+                except (NameError, KeyError, ValueError) as e:
+                    pytest.fail(
+                        f"{filename}:{line_no}: caller channel expression "
+                        f"`{ch_expr}` uses symbol outside {{ch}} or a "
+                        f"disallowed operator ({e}). Extend "
+                        f"_safe_eval_int_expr variables or rewrite the "
+                        f"call site with a supported expression."
+                    )
+                for base_sym, offset_expr, stride in helpers:
+                    try:
+                        offset = _safe_eval_int_expr(
+                            offset_expr, channel=channel_val,
+                        )
+                    except (NameError, KeyError, ValueError) as e:
+                        pytest.fail(
+                            f"helper `{setter}` offset expr "
+                            f"`{offset_expr}` uses symbol outside "
+                            f"{{channel}} or a disallowed operator ({e}). "
+                            f"Extend _safe_eval_int_expr variables if new "
+                            f"driver state is introduced."
+                        )
+                    final = self.reg_map[base_sym] + offset * stride
+                    expected_sym = base_sym.replace("CH1", f"CH{ch + 1}")
+                    expected = self.reg_map[expected_sym]
+                    if final != expected:
+                        errors.append(
+                            f"  - {filename}:{line_no} {setter} "
+                            f"caller `{ch_expr}` | ch={ch} -> "
+                            f"channel={channel_val} -> "
+                            f"`{base_sym} + ({offset_expr})"
+                            f"{' * ' + str(stride) if stride != 1 else ''}`"
+                            f" = 0x{final:03X} "
+                            f"(expected {expected_sym} = 0x{expected:03X})"
+                        )
+        assert not errors, (
+            f"ADAR1000 channel round-trip FAILED for {setter} "
+            f"({len(errors)} mismatches) — writes routed to wrong physical "
+            f"channel. This is issue #90.\n" + "\n".join(errors)
+        )
+
+
 class TestTier1DataPacketLayout:
    """Verify data packet byte layout matches between Python and Verilog."""

@@ -468,6 +1154,204 @@ class TestTier1STM32SettingsPacket:
        assert flag == [23, 46, 158, 237], f"Start flag: {flag}"


+# ===================================================================
+# TIER 2: ADAR1000 Vector Modulator Lookup-Table Ground Truth
+# ===================================================================
+#
+# Cross-layer contract: the firmware constants
+#   ADAR1000Manager::VM_I[128] / VM_Q[128]
+# (in 9_Firmware/9_1_Microcontroller/9_1_1_C_Cpp_Libraries/ADAR1000_Manager.cpp)
+# MUST equal the byte values published in the ADAR1000 datasheet Rev. B,
+# Tables 13-16 page 34 ("Phase Shifter Programming"), on a uniform 2.8125 deg
+# grid (index N == phase N * 360/128 deg).
+#
+# Independent ground truth lives in tools/verify_adar1000_vm_tables.py
+# (transcribed from the datasheet, cross-checked against the ADI Linux
+# beamformer driver as a secondary source). This test imports that
+# reference and asserts a byte-exact match.
+#
+# Historical bug guarded against: from initial commit through PR #94 the
+# arrays shipped as empty placeholders ("// ... (same as in your original
+# file)"), so every adarSetRxPhase / adarSetTxPhase call wrote I=Q=0 and
+# beam steering was non-functional. A separate VM_GAIN[128] table was
+# declared but never read anywhere; this test also enforces its removal so
+# it cannot be reintroduced and silently shadow real bugs.
+
+class TestTier2Adar1000VmTableGroundTruth:
+    """Firmware ADAR1000 VM_I/VM_Q must match datasheet ground truth byte-exact."""
+
+    @pytest.fixture(scope="class")
+    def cpp_source(self):
+        path = (
+            cp.REPO_ROOT
+            / "9_Firmware"
+            / "9_1_Microcontroller"
+            / "9_1_1_C_Cpp_Libraries"
+            / "ADAR1000_Manager.cpp"
+        )
+        assert path.is_file(), f"Firmware source missing: {path}"
+        return path.read_text()
+
+    def test_ground_truth_table_shape(self):
+        """Sanity-check the imported reference (defends against import-path mishap)."""
+        gt = adar_vm.GROUND_TRUTH
+        assert len(gt) == 128, "Ground-truth table must have exactly 128 entries"
+        # Each row is (deg_int, deg_frac_e4, vm_i_byte, vm_q_byte)
+        for k, row in enumerate(gt):
+            assert len(row) == 4, f"Row {k} malformed: {row}"
+            assert 0 <= row[2] <= 0xFF, f"VM_I[{k}] out of byte range: {row[2]:#x}"
+            assert 0 <= row[3] <= 0xFF, f"VM_Q[{k}] out of byte range: {row[3]:#x}"
+            # Byte format: bits[7:6] reserved zero, bits[5] polarity, bits[4:0] mag
+            assert (row[2] & 0xC0) == 0, f"VM_I[{k}] reserved bits set: {row[2]:#x}"
+            assert (row[3] & 0xC0) == 0, f"VM_Q[{k}] reserved bits set: {row[3]:#x}"
+
+    def test_ground_truth_byte_format(self):
+        """Transcription self-check: every VM_I/VM_Q byte has reserved bits clear."""
+        errors = adar_vm.check_byte_format("VM_I_REF", adar_vm.VM_I_REF)
+        errors += adar_vm.check_byte_format("VM_Q_REF", adar_vm.VM_Q_REF)
+        assert not errors, (
+            "Byte-format violations in embedded GROUND_TRUTH (likely transcription "
+            "typo from ADAR1000 datasheet Tables 13-16):\n  " + "\n  ".join(errors)
+        )
+
+    def test_ground_truth_uniform_2p8125_deg_grid(self):
+        """Transcription self-check: angles form a uniform 2.8125 deg grid.
+
+        This is the assumption that lets the firmware use `VM_*[phase % 128]`
+        as a direct index (no nearest-neighbour search). If the embedded
+        angles drift off the grid, the firmware's indexing model is wrong.
+        """
+        errors = adar_vm.check_uniform_2p8125_deg_step()
+        assert not errors, (
+            "Non-uniform angle grid in GROUND_TRUTH:\n  " + "\n  ".join(errors)
+        )
+
+    def test_ground_truth_quadrant_symmetry(self):
+        """Transcription self-check: phi and phi+180 deg have same magnitude,
+        opposite polarity. Catches swapped/rotated rows in the table.
+        """
+        errors = adar_vm.check_quadrant_symmetry()
+        assert not errors, (
+            "Quadrant-symmetry violation in GROUND_TRUTH (table rows may be "
+            "transposed or mis-transcribed):\n  " + "\n  ".join(errors)
+        )
+
+    def test_ground_truth_cardinal_points(self):
+        """Transcription self-check: the four cardinal phases (0, 90, 180,
+        270 deg) match the datasheet-published extrema exactly.
+        """
+        errors = adar_vm.check_cardinal_points()
+        assert not errors, (
+            "Cardinal-point mismatch in GROUND_TRUTH vs ADAR1000 datasheet "
+            "Tables 13-16:\n  " + "\n  ".join(errors)
+        )
+
+    def test_firmware_vm_i_matches_datasheet(self, cpp_source):
+        gt = adar_vm.GROUND_TRUTH
+        firmware = adar_vm.parse_array(cpp_source, "VM_I")
+        assert firmware is not None, (
+            "Could not parse VM_I[128] from ADAR1000_Manager.cpp; "
+            "definition pattern may have drifted"
+        )
+        assert len(firmware) == 128, (
+            f"VM_I has {len(firmware)} entries, expected 128. "
+            "Empty placeholder regression — every phase write would emit I=0 "
+            "and beam steering would be silently broken."
+        )
+        mismatches = [
+            (k, firmware[k], gt[k][2])
+            for k in range(128)
+            if firmware[k] != gt[k][2]
+        ]
+        assert not mismatches, (
+            f"VM_I diverges from datasheet at {len(mismatches)} indices; "
+            f"first 5: {mismatches[:5]}"
+        )
+
+    def test_firmware_vm_q_matches_datasheet(self, cpp_source):
+        gt = adar_vm.GROUND_TRUTH
+        firmware = adar_vm.parse_array(cpp_source, "VM_Q")
+        assert firmware is not None, (
+            "Could not parse VM_Q[128] from ADAR1000_Manager.cpp; "
+            "definition pattern may have drifted"
+        )
+        assert len(firmware) == 128, (
+            f"VM_Q has {len(firmware)} entries, expected 128. "
+            "Empty placeholder regression — every phase write would emit Q=0."
+        )
+        mismatches = [
+            (k, firmware[k], gt[k][3])
+            for k in range(128)
+            if firmware[k] != gt[k][3]
+        ]
+        assert not mismatches, (
+            f"VM_Q diverges from datasheet at {len(mismatches)} indices; "
+            f"first 5: {mismatches[:5]}"
+        )
+
+    def test_vm_gain_table_is_not_reintroduced(self, cpp_source):
+        """Dead-code regression guard: VM_GAIN[128] must not exist as code.
+
+        The ADAR1000 vector modulator has no separate gain register; magnitude
+        is bits[4:0] of the I/Q bytes themselves. Per-channel VGA gain uses
+        registers CHx_RX_GAIN (0x10-0x13) / CHx_TX_GAIN (0x1C-0x1F) written
+        directly by adarSetRxVgaGain / adarSetTxVgaGain. A VM_GAIN[] array
+        was declared in early development, never populated, never read, and
+        was removed in PR fix/adar1000-vm-tables. Reintroducing it would
+        suggest (falsely) that an extra lookup is needed and could mask the
+        real signal path.
+
+        Uses a tokenising comment/string stripper so that the historical
+        explanation comment in the cpp file, as well as any string literal
+        containing the substring "VM_GAIN", does not trip the check.
+        """
+        stripped = _strip_cxx_comments_and_strings(cpp_source)
+        assert "VM_GAIN" not in stripped, (
+            "VM_GAIN symbol reappeared in ADAR1000_Manager.cpp executable code. "
+            "This array has no hardware backing and must not be reintroduced. "
+            "If you need to scale phase-state magnitude, modify VM_I/VM_Q "
+            "bits[4:0] directly per the datasheet."
+        )
+
+    def test_adversarial_corruption_is_detected(self):
+        """Adversarial self-test: a flipped byte in firmware MUST fail comparison.
+
+        Defends against silent bypass — e.g. a future refactor that mocks
+        parse_array() or compares len() only. We synthesise a corrupted cpp
+        source string, run the same parser, and assert mismatch is detected.
+        """
+        gt = adar_vm.GROUND_TRUTH
+        # Build a minimal valid-looking cpp snippet with one corrupted byte.
+        good_i = ", ".join(f"0x{gt[k][2]:02X}" for k in range(128))
+        good_q = ", ".join(f"0x{gt[k][3]:02X}" for k in range(128))
+        snippet_good = (
+            f"const uint8_t ADAR1000Manager::VM_I[128] = {{ {good_i} }};\n"
+            f"const uint8_t ADAR1000Manager::VM_Q[128] = {{ {good_q} }};\n"
+        )
+        # Sanity: the unmodified snippet must parse and match.
+        parsed_i = adar_vm.parse_array(snippet_good, "VM_I")
+        assert parsed_i is not None and len(parsed_i) == 128
+        assert all(parsed_i[k] == gt[k][2] for k in range(128)), (
+            "Self-test setup error: golden snippet does not match GROUND_TRUTH"
+        )
+        # Now flip the low bit of VM_I[42] and confirm detection.
+        corrupted_byte = gt[42][2] ^ 0x01
+        bad_i = ", ".join(
+            f"0x{(corrupted_byte if k == 42 else gt[k][2]):02X}"
+            for k in range(128)
+        )
+        snippet_bad = (
+            f"const uint8_t ADAR1000Manager::VM_I[128] = {{ {bad_i} }};\n"
+            f"const uint8_t ADAR1000Manager::VM_Q[128] = {{ {good_q} }};\n"
+        )
+        parsed_bad = adar_vm.parse_array(snippet_bad, "VM_I")
+        assert parsed_bad is not None and len(parsed_bad) == 128
+        assert parsed_bad[42] != gt[42][2], (
+            "Adversarial self-test FAILED: corrupted byte at index 42 was "
+            "not detected by parse_array. The cross-layer test is bypassable."
+        )
+
+
 # ===================================================================
 # TIER 2: Verilog Cosimulation
 # ===================================================================
@@ -5,140 +5,109 @@ for getting a change reviewed and merged.

 ## Getting started

-1. Fork the repository and create a topic branch from `develop`.
-2. Keep generated outputs (Vivado projects, bitstreams, build logs)
-   out of version control — the `.gitignore` already covers most of
-   these.
+1. Fork the repository and create a topic branch from `develop`. The `main` branch is for production releases only.
+2. Keep generated outputs (Vivado projects, bitstreams, build logs) out of version control.
+
+### Security Mandate: Package Installation
+Due to supply chain attack risks, **ALL package installations MUST use the `sfw` (secure firewall) prefix**.
+- Python: `sfw uv pip install <package>` (Do not use raw pip)
+- Node/JS: `sfw npm install <package>`
+- Rust/Cargo: `sfw cargo <command>`
+
+Never run bare package installation commands without the `sfw` prefix.

 ## Repository layout

 | Path | Contents |
 |------|----------|
 | `4_Schematics and Boards Layout/` | KiCad schematics, Gerbers, BOM/CPL |
+| `9_Firmware/9_1_Microcontroller/` | STM32 MCU C/C++ firmware and unit tests |
 | `9_Firmware/9_2_FPGA/` | Verilog RTL, constraints, testbenches, build scripts |
-| `9_Firmware/9_2_FPGA/formal/` | SymbiYosys formal-verification wrappers |
-| `9_Firmware/9_2_FPGA/scripts/` | Vivado TCL build & debug scripts |
-| `9_Firmware/9_3_GUI/` | Python radar dashboard (Tkinter + matplotlib) |
+| `9_Firmware/9_3_GUI/` | Python radar dashboard (Tkinter/PyQt6) and CLI tools |
+| `9_Firmware/tests/cross_layer/` | Python-based system invariant/contract tests |
 | `docs/` | GitHub Pages documentation site |

-## Before submitting a pull request
+## Code Standards & Tooling

- **Python** — verify syntax: `python3 -m py_compile <file>`
- **Verilog** — if you have Vivado, run the relevant `build*.tcl`;
-  if not, note which scripts your change affects
- **Whitespace** — `git diff --check` should be clean
- Keep PRs focused: one logical change per PR is easier to review
- **Run the regression tests** (see below)
+- **Python (GUI, Scripts, Tests)**:
+  - We use `uv` for dependency management.
+  - We strictly enforce linting with `ruff`. Run `uv run ruff check .` before committing.
+  - Test with `pytest`.
+- **Verilog (FPGA)**:
+  - The RTL (`radar_system_top.v`) is the single source of truth for opcode values, bit widths, reset defaults, and valid ranges.
+  - Testbenches must include **adversarial validation**: actively test boundary conditions, race conditions, unexpected input sequences, and reset mid-operation.
+  - Use `iverilog` for simulation.
+- **C/C++ (MCU)**:
+  - Use `make test` for host-side unit testing (cpputest).
+- **System-Level Invariants**:
+  - Whenever adding code, verify that system-level invariants (across module, process, and chip boundaries) hold true.

-## Running regression tests
+## AI Usage Policy

-After any change, run the relevant test suites to verify nothing is
-broken. All commands assume you are at the repository root.
+The use of AI is permitted but we have to make sure that the quality and control of the codebase doesn't depend on the agents but the maintainer pushing the changes, meaning they are fully responsible for the code they commit.

-### Prerequisites
+1. **Human Accountability** — The committing engineer is fully responsible for AI-generated code as if they wrote it. Every PR must be understood and defensible by a human.
+2. **Mandatory Review** — No raw AI output may be committed unread. AI code must pass the same review bar as hand-written code.
+3. **Full CI Before Commit** — All AI-assisted changes must pass the complete CI suite locally (lint, unit, regression, cross-layer) before commit.

-| Tool | Used by | Install |
-|------|---------|---------|
-| [Icarus Verilog](http://iverilog.icarus.com/) (`iverilog`) | FPGA regression | `brew install icarus-verilog` / `apt install iverilog` |
-| Python 3.8+ | GUI tests, co-sim | Usually pre-installed |
-| GNU Make | MCU tests | Usually pre-installed |
-| [SymbiYosys](https://symbiyosys.readthedocs.io/) (`sby`) | Formal verification | Optional — see SymbiYosys docs |
+## Running the Test Suites

-### FPGA regression (RTL lint + unit/integration/signal-processing tests)
+We use GitHub Actions for CI, which runs four main jobs on every PR. Run these locally before pushing.

+### 1. Python & Linting
+```bash
+uv run ruff check .
+cd 9_Firmware/9_3_GUI
+uv run pytest test_GUI_V65_Tk.py test_v7.py -v
+```
+
+### 2. FPGA Regression
 ```bash
 cd 9_Firmware/9_2_FPGA
 bash run_regression.sh
 ```
+This runs five phases (Lint, Changed Modules, Integration, Signal Processing, Infrastructure, and **P0 Adversarial Tests**). All must pass.

-This runs four phases:
-
-| Phase | What it checks |
-|-------|----------------|
-| 0 — Lint | `iverilog -Wall` on all production RTL + static regex checks |
-| 1 — Changed Modules | Unit tests for individual blocks (CIC, Doppler, CFAR, etc.) |
-| 2 — Integration | DDC chain, receiver golden-compare, system-top, end-to-end |
-| 3 — Signal Processing | FFT engine, NCO, FIR, matched filter chain |
-| 4 — Infrastructure | CDC modules, edge detector, USB interface, range-bin decimator, mode controller |
-
-All tests must pass (exit code 0). Advisory lint warnings (e.g., `case
-without default`) are non-blocking.
-
-### MCU unit tests
-
+### 3. MCU Unit Tests
 ```bash
 cd 9_Firmware/9_1_Microcontroller/tests
-make clean && make all
+make clean && make
 ```

-Runs 20 C-based unit tests covering safety, bug-fix, and gap-3 tests.
-Every test binary must exit 0.
-
-### GUI / dashboard tests
-
+### 4. Cross-Layer Contract Tests
 ```bash
-cd 9_Firmware/9_3_GUI
-python3 -m pytest test_GUI_V65_Tk.py -v
-# or without pytest:
-python3 -m unittest test_GUI_V65_Tk -v
+uv run pytest 9_Firmware/tests/cross_layer/test_cross_layer_contract.py -v
 ```

-57+ protocol and rendering tests. The `test_record_and_stop` test
-requires `h5py` and will be skipped if it is not installed.
+## Before merging: CI checklist

-### Co-simulation (Python vs RTL golden comparison)
+All PRs must pass CI:

-Run from the co-sim directory after a successful FPGA regression (the
-regression generates the RTL CSV outputs that the co-sim scripts compare
-against):
+| Job | What it checks |
+|----|---------------|
+| `python-tests` | ruff clean + pytest green |
+| `mcu-tests` | make all exits 0 |
+| `fpga-regression` | run_regression.sh exits 0 |
+| `cross-layer-tests` | pytest exits 0 |

-```bash
-cd 9_Firmware/9_2_FPGA/tb/cosim
+## Important Notes

-# Validate all .mem files (twiddles, chirp ROMs, addressing)
-python3 validate_mem_files.py
+- **NO LEGACY COMPATIBILITY** unless explicitly requested by the maintainer.
+- **The FPGA RTL (`radar_system_top.v`) is the single source of truth** for opcode values, bit widths, reset defaults, and valid ranges. All other layers must align to it.
+- **Adversarial testing is mandatory**: Every test must actively try to break the code.
+- **Testbench timing**: Always add a `#1` delay after `@(posedge clk)` before driving DUT inputs with blocking assignments.
+- **Pre-fetch FIFO**: Remember `wr_full` is asserted after DEPTH+1 writes, not just DEPTH.

-# DDC chain: RTL vs Python model (5 scenarios)
-python3 compare.py dc
-python3 compare.py single_target
-python3 compare.py multi_target
-python3 compare.py noise_only
-python3 compare.py sine_1mhz
+## Checklist Before Push

-# Doppler processor: RTL vs golden reference
-python3 compare_doppler.py stationary
-
-# Matched filter: RTL vs Python model (4 scenarios)
-python3 compare_mf.py all
-```
-
-Each script prints PASS/FAIL per scenario and exits non-zero on failure.
-
-### Formal verification (optional)
-
-Requires SymbiYosys (`sby`), Yosys, and a solver (z3 or boolector):
-
-```bash
-cd 9_Firmware/9_2_FPGA/formal
-sby -f fv_doppler_processor.sby
-sby -f fv_radar_mode_controller.sby
-```
-
-### Quick checklist
-
-Before pushing, confirm:
-
-1. `bash run_regression.sh` — all phases pass
-2. `make all` (MCU tests) — 20/20 pass
-3. `python3 -m unittest test_GUI_V65_Tk -v` — all pass
-4. `python3 validate_mem_files.py` — all checks pass
-5. `python3 compare.py dc && python3 compare_doppler.py stationary && python3 compare_mf.py all`
-6. `git diff --check` — no whitespace issues
-
-## Areas where help is especially welcome
-
-See the list in [README.md](README.md#-contributing).
+- [ ] `uv run ruff check .` — no lint errors
+- [ ] `uv run pytest test_GUI_V65_Tk.py test_v7.py -v` — all pass
+- [ ] `cd 9_Firmware/9_2_FPGA && bash run_regression.sh` — all 5 phases pass
+- [ ] `cd 9_Firmware/9_1_Microcontroller/tests && make clean && make` — pass
+- [ ] `uv run pytest 9_Firmware/tests/cross_layer/test_cross_layer_contract.py` — pass
+- [ ] `git diff --check` — no whitespace issues
+- [ ] PR targets `develop` branch

 ## Questions?

-Open a GitHub issue — that way the discussion is visible to everyone.
+Open a GitHub issue — discussion is visible to everyone.
@@ -53,7 +53,7 @@ The AERIS-10 main sub-systems are:
  - **XC7A50T FPGA** - Handles RADAR Signal Processing on the upstream FTG256 board:
    - PLFM Chirps generation via the DAC
    - Raw ADC data read
-    - Digital Gain Control (host-configurable gain shift)
+    - Hybrid Automatic Gain Control (AGC) — cross-layer FPGA/STM32/GUI loop
    - I/Q Baseband Down-Conversion
    - Decimation
    - Filtering
@@ -68,13 +68,13 @@ The AERIS-10 main sub-systems are:
      - Clock Generator (AD9523-1)
      - 2x Frequency Synthesizers (ADF4382)
      - 4x 4-Channel Phase Shifters (ADAR1000) for RADAR pulse sequencing
-      - 2x ADS7830 ADCs (on Power Amplifier Boards) for Idq measurement
-      - 2x DAC5578 (on Power Amplifier Boards) for Vg control
-      - GPS module for GUI map centering
+      - 2x ADS7830 8-channel I²C ADCs (Main Board, U88 @ 0x48 / U89 @ 0x4A) for 16x Idq measurement, one per PA channel, each sensed through a 5 mΩ shunt on the PA board and an INA241A3 current-sense amplifier (x50) on the Main Board
+      - 2x DAC5578 8-channel I²C DACs (Main Board, U7 @ 0x48 / U69 @ 0x49) for 16x Vg control, one per PA channel; closed-loop calibrated at boot to the target Idq
+      - GPS module (UM982) for GUI map centering and per-detection position tagging
      - GY-85 IMU for pitch/roll correction of target coordinates
      - BMP180 Barometer
      - Stepper Motor
-      - 8x ADS7830 Temperature Sensors for cooling fan control
+      - 1x ADS7830 8-channel I²C ADC (Main Board, U10) reading 8 thermistors for thermal monitoring; a single GPIO (EN_DIS_COOLING) switches the cooling fans on when any channel exceeds the threshold
      - RF switches

 - **16x Power Amplifier Boards** - Used only for AERIS-10E version, featuring 10Watt QPA2962 GaN amplifier for extended range
@@ -111,7 +111,8 @@ The AERIS-10 main sub-systems are:
   - Map integration
   - Radar control interface

-![AERIS-10 GUI Demo](https://raw.githubusercontent.com/NawfalMotii79/PLFM_RADAR/main/8_Utils/GUI_V6.gif)
+![AERIS-10 Dashboard](https://raw.githubusercontent.com/NawfalMotii79/PLFM_RADAR/main/8_Utils/GUI_V6.gif)
+<!-- V6 GIF removed — V6 is deprecated. V65 Tk and V7 PyQt6 are the active GUIs. -->

 ## 📊 Technical Specifications

@@ -32,6 +32,11 @@
    </section>

    <section class="stats-grid">
+      <article class="card stat notice">
+        <h2>Production Board USB</h2>
+        <p class="metric">FT2232H (USB 2.0)</p>
+        <p class="muted">50T production board uses FT2232H. FT601 USB 3.0 is available on 200T premium dev board only.</p>
+      </article>
      <article class="card stat">
        <h2>Tracked Timing Baseline</h2>
        <p class="metric">WNS +0.058 ns</p>