Fix chirp memory loader BRAM async reset (Gap 5, REQP-1839/1840)

9_Firmware/9_2_FPGA/chirp_memory_loader_param.v

@@ -103,18 +103,19 @@ initial begin
 end
 
 // Memory access logic
-reg [11:0] long_addr;
+// long_addr is combinational — segment_select[1:0] concatenated with sample_addr[9:0]
+wire [11:0] long_addr = {segment_select, sample_addr};
 
-always @(posedge clk or negedge reset_n) begin
+// ---- BRAM read block (sync-only, sync reset) ----
+// REQP-1839/1840 fix: BRAM output registers cannot have async resets.
+// We use a synchronous reset instead, which Vivado maps to the BRAM
+// RSTREGB port (supported by 7-series BRAM primitives).
+always @(posedge clk) begin
     if (!reset_n) begin
         ref_i <= 16'd0;
         ref_q <= 16'd0;
-        mem_ready <= 1'b0;
-    end else begin
-        if (mem_request) begin
+    end else if (mem_request) begin
         if (use_long_chirp) begin
-                // Direct addressing for 4 segments
-                long_addr = {segment_select, sample_addr};  // segment_select[1:0] + sample_addr[9:0]
             ref_i <= long_chirp_i[long_addr];
             ref_q <= long_chirp_q[long_addr];
             
@@ -137,11 +138,16 @@ always @(posedge clk or negedge reset_n) begin
             end
             `endif
         end
-            mem_ready <= 1'b1;
-        end else begin
-            mem_ready <= 1'b0;
     end
 end
+
+// ---- Control block (async reset for mem_ready only) ----
+always @(posedge clk or negedge reset_n) begin
+    if (!reset_n) begin
+        mem_ready <= 1'b0;
+    end else begin
+        mem_ready <= mem_request;
+    end
 end
 
 endmodule