Squashed B200 FPGA Source. Code from Josh Blum, Ian Buckley, and Matt Ettus.

Original-commit: 0df4b801a34697f2058b4a7b95e08d2a0576c9db

lib/dsp/rx_frontend.v

@@ -0,0 +1,78 @@
+
+module rx_frontend
+  #(parameter BASE = 0,
+    parameter IQCOMP_EN = 1)
+   (input clk, input rst,
+    input set_stb, input [7:0] set_addr, input [31:0] set_data,
+
+    input [15:0] adc_a, input adc_ovf_a,
+    input [15:0] adc_b, input adc_ovf_b,
+
+    output [23:0] i_out, output [23:0] q_out,
+    input run,
+    output [31:0] debug
+    );
+   
+   reg [15:0] 	  adc_i, adc_q;
+   wire [17:0] 	  adc_i_ofs, adc_q_ofs;
+   wire [35:0] 	  corr_i, corr_q; wire [17:0] 	  mag_corr,phase_corr;
+   wire 	  swap_iq;
+   
+   setting_reg #(.my_addr(BASE), .width(1)) sr_8
+     (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr),
+      .in(set_data),.out(swap_iq),.changed());
+
+   always @(posedge clk)
+     if(swap_iq) // Swap
+       {adc_i,adc_q} <= {adc_b,adc_a};
+     else
+       {adc_i,adc_q} <= {adc_a,adc_b};
+       
+   setting_reg #(.my_addr(BASE+1),.width(18)) sr_1
+     (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr),
+      .in(set_data),.out(mag_corr),.changed());
+   
+   setting_reg #(.my_addr(BASE+2),.width(18)) sr_2
+     (.clk(clk),.rst(rst),.strobe(set_stb),.addr(set_addr),
+      .in(set_data),.out(phase_corr),.changed());
+
+   generate
+      if(IQCOMP_EN == 1)
+	begin
+	   rx_dcoffset #(.WIDTH(18),.ADDR(BASE+3)) rx_dcoffset_i
+	     (.clk(clk),.rst(rst),.set_stb(set_stb),.set_addr(set_addr),.set_data(set_data),
+	      .in({adc_i,2'b00}),.out(adc_i_ofs));
+	   
+	   rx_dcoffset #(.WIDTH(18),.ADDR(BASE+4)) rx_dcoffset_q
+	     (.clk(clk),.rst(rst),.set_stb(set_stb),.set_addr(set_addr),.set_data(set_data),
+	      .in({adc_q,2'b00}),.out(adc_q_ofs));
+	   
+	   MULT18X18S mult_mag_corr
+	     (.P(corr_i), .A(adc_i_ofs), .B(mag_corr), .C(clk), .CE(1), .R(rst) ); 
+	   
+	   MULT18X18S mult_phase_corr
+	     (.P(corr_q), .A(adc_i_ofs), .B(phase_corr), .C(clk), .CE(1), .R(rst) );
+	   
+	   add2_and_clip_reg #(.WIDTH(24)) add_clip_i
+	     (.clk(clk), .rst(rst), 
+	      .in1({adc_i_ofs,6'd0}), .in2(corr_i[35:12]), .strobe_in(1'b1),
+	      .sum(i_out), .strobe_out());
+	   
+	   add2_and_clip_reg #(.WIDTH(24)) add_clip_q
+	     (.clk(clk), .rst(rst), 
+	      .in1({adc_q_ofs,6'd0}), .in2(corr_q[35:12]), .strobe_in(1'b1),
+	      .sum(q_out), .strobe_out());
+	end // if (IQCOMP_EN == 1)
+      else
+	begin
+	   rx_dcoffset #(.WIDTH(24),.ADDR(BASE+3)) rx_dcoffset_i
+	     (.clk(clk),.rst(rst),.set_stb(set_stb),.set_addr(set_addr),.set_data(set_data),
+	      .in({adc_i,8'b00}),.out(i_out));
+	   
+	   rx_dcoffset #(.WIDTH(24),.ADDR(BASE+4)) rx_dcoffset_q
+	     (.clk(clk),.rst(rst),.set_stb(set_stb),.set_addr(set_addr),.set_data(set_data),
+	      .in({adc_q,8'b00}),.out(q_out));
+	end // else: !if(IQCOMP_EN == 1)
+      endgenerate
+   
+endmodule // rx_frontend