From a7e55c752ff0f615eee8e26833dd68938e069b69 Mon Sep 17 00:00:00 2001
From: NawfalMotii79 <nawfal.motii.33@gmail.com>
Date: Tue, 10 Mar 2026 01:36:04 +0000
Subject: [PATCH] Create usb_packet_analyzer.v

---
 9_Firmware/9_2_FPGA/usb_packet_analyzer.v | 134 ++++++++++++++++++++++
 1 file changed, 134 insertions(+)
 create mode 100644 9_Firmware/9_2_FPGA/usb_packet_analyzer.v

diff --git a/9_Firmware/9_2_FPGA/usb_packet_analyzer.v b/9_Firmware/9_2_FPGA/usb_packet_analyzer.v
new file mode 100644
index 0000000..508e838
--- /dev/null
+++ b/9_Firmware/9_2_FPGA/usb_packet_analyzer.v
@@ -0,0 +1,134 @@
+`timescale 1ns / 1ps
+
+/**
+ * usb_packet_analyzer.v
+ * 
+ * Analyzes USB packet format from FT601 interface
+ * Verifies header/footer and data integrity
+ */
+
+module usb_packet_analyzer (
+    input wire clk,
+    input wire reset_n,
+    input wire [31:0] usb_data,
+    input wire usb_wr_strobe,
+    output reg packet_valid,
+    output reg [7:0] packet_type,
+    output reg [31:0] packet_data,
+    output reg [31:0] error_count
+);
+
+// Packet structure
+localparam HEADER = 8'hAA;
+localparam FOOTER = 8'h55;
+localparam HEADER_POS = 24;  // Header in bits [31:24]
+
+// States
+typedef enum {
+    ST_IDLE,
+    ST_HEADER,
+    ST_RANGE,
+    ST_DOPPLER,
+    ST_DETECTION,
+    ST_FOOTER
+} state_t;
+
+state_t current_state, next_state;
+reg [7:0] byte_count;
+reg [31:0] error_reg;
+reg [31:0] packet_count;
+
+always @(posedge clk or negedge reset_n) begin
+    if (!reset_n) begin
+        current_state <= ST_IDLE;
+        byte_count <= 8'd0;
+        error_reg <= 32'd0;
+        packet_count <= 32'd0;
+        packet_valid <= 1'b0;
+        packet_type <= 8'd0;
+        packet_data <= 32'd0;
+    end else begin
+        packet_valid <= 1'b0;
+        
+        case (current_state)
+            ST_IDLE: begin
+                if (usb_wr_strobe && usb_data[31:24] == HEADER) begin
+                    current_state <= ST_HEADER;
+                    packet_count <= packet_count + 1;
+                    $display("[USB_ANALYZER] Packet %0d started at time %0t", 
+                             packet_count + 1, $time);
+                end
+            end
+            
+            ST_HEADER: begin
+                if (usb_wr_strobe) begin
+                    current_state <= ST_RANGE;
+                    byte_count <= 8'd0;
+                end
+            end
+            
+            ST_RANGE: begin
+                if (usb_wr_strobe) begin
+                    if (byte_count == 8'd0) begin
+                        packet_data[31:24] <= usb_data[7:0];
+                        byte_count <= 8'd1;
+                    end else if (byte_count == 8'd1) begin
+                        packet_data[23:16] <= usb_data[7:0];
+                        byte_count <= 8'd2;
+                    end else if (byte_count == 8'd2) begin
+                        packet_data[15:8] <= usb_data[7:0];
+                        byte_count <= 8'd3;
+                    end else if (byte_count == 8'd3) begin
+                        packet_data[7:0] <= usb_data[7:0];
+                        current_state <= ST_DOPPLER;
+                        byte_count <= 8'd0;
+                        $display("[USB_ANALYZER] Range data: 0x%08h", packet_data);
+                    end
+                end
+            end
+            
+            ST_DOPPLER: begin
+                if (usb_wr_strobe) begin
+                    if (byte_count == 8'd0) begin
+                        packet_data[31:16] <= usb_data[31:16];  // Doppler real
+                        byte_count <= 8'd1;
+                    end else if (byte_count == 8'd1) begin
+                        packet_data[15:0] <= usb_data[31:16];   // Doppler imag
+                        current_state <= ST_DETECTION;
+                        byte_count <= 8'd0;
+                        $display("[USB_ANALYZER] Doppler data: real=0x%04h, imag=0x%04h",
+                                 packet_data[31:16], packet_data[15:0]);
+                    end
+                end
+            end
+            
+            ST_DETECTION: begin
+                if (usb_wr_strobe) begin
+                    packet_type <= usb_data[0];
+                    current_state <= ST_FOOTER;
+                    $display("[USB_ANALYZER] Detection: %b", usb_data[0]);
+                end
+            end
+            
+            ST_FOOTER: begin
+                if (usb_wr_strobe) begin
+                    if (usb_data[7:0] == FOOTER) begin
+                        packet_valid <= 1'b1;
+                        $display("[USB_ANALYZER] Packet %0d valid, footer OK", packet_count);
+                    end else begin
+                        error_reg <= error_reg + 1;
+                        $error("[USB_ANALYZER] Invalid footer: expected 0x55, got 0x%02h",
+                               usb_data[7:0]);
+                    end
+                    current_state <= ST_IDLE;
+                end
+            end
+            
+            default: current_state <= ST_IDLE;
+        endcase
+    end
+end
+
+assign error_count = error_reg;
+
+endmodule