Merged r5463:5504 from jcorgan/snd into trunk. Work in progress, adds digital loopbac...

[debian/gnuradio] / gr-sounder / src / fpga / lib / sounder.v

diff --git a/gr-sounder/src/fpga/lib/sounder.v b/gr-sounder/src/fpga/lib/sounder.v
index ea4007cb84a5e9115ce1887007e5bf806e66954f..58b563448d98e6bbe5af30fd353f270276a0e735 100644 (file)
--- a/gr-sounder/src/fpga/lib/sounder.v
+++ b/gr-sounder/src/fpga/lib/sounder.v
@@ -22,10 +22,10 @@
 `include "../../../../usrp/firmware/include/fpga_regs_common.v"
 `include "../../../../usrp/firmware/include/fpga_regs_standard.v"
 
-module sounder(clk_i,saddr_i,sdata_i,s_strobe_i,tx_rst_i,tx_enable_i,tx_strobe_i,
-              tx_dac_i_o,tx_dac_q_o,
-              rx_rst_i,rx_enable_i,rx_strobe_i,rx_strobe_o,
-              rx_adc_i_i,rx_adc_q_i,rx_imp_i_o,rx_imp_q_o);
+module sounder(clk_i, saddr_i, sdata_i, s_strobe_i,
+              tx_strobe_i, tx_dac_i_o,tx_dac_q_o,
+              rx_strobe_i, rx_adc_i_i,rx_adc_q_i,
+              rx_strobe_o, rx_imp_i_o,rx_imp_q_o);
 
    // System interface
    input         clk_i;                // Master clock @ 64 MHz
@@ -34,53 +34,59 @@ module sounder(clk_i,saddr_i,sdata_i,s_strobe_i,tx_rst_i,tx_enable_i,tx_strobe_i
    input        s_strobe_i;    // Configuration bus write
    
    // Transmit subsystem
-   input         tx_rst_i;     // Independent subsystem reset
-   input         tx_enable_i;  // Turn on transmitter functionality
    input         tx_strobe_i;  // Generate an transmitter output sample
-   output [15:0] tx_dac_i_o;   // I channel transmitter output to DAC
-   output [15:0] tx_dac_q_o;    // Q channel transmitter output to DAC
+   output [13:0] tx_dac_i_o;   // I channel transmitter output to DAC
+   output [13:0] tx_dac_q_o;    // Q channel transmitter output to DAC
 
    // Receive subsystem
-   input        rx_rst_i;      // Independent subsystem reset
-   input        rx_enable_i;   // Turn on receiver functionality
    input         rx_strobe_i;  // Indicates receive sample ready from ADC
    output       rx_strobe_o;   // Indicates output samples ready for Rx FIFO
-   input  [15:0] rx_adc_i_i;   // I channel input from ADC
-   input  [15:0] rx_adc_q_i;   // Q channel input from ADC
+   input  [15:0] rx_adc_i_i;   // I channel input from ADC interface module
+   input  [15:0] rx_adc_q_i;   // Q channel input from ADC interface module
    output [15:0] rx_imp_i_o;   // I channel impulse response to Rx FIFO
    output [15:0] rx_imp_q_o;   // Q channel impulse response to Rx FIFO
+        
+   // Internal variables
+   wire          reset;
+   wire         transmit;
+   wire         receive;
+   wire         loopback;
 
-   // Configuration
-   wire   [4:0]  degree;       // LFSR register length
-   wire   [15:0] mask;         // LFSR parity mask
-   wire   [15:0] len;          // PN code sequence length
-   wire          loopback;     // Enable digital loopback
+   wire [4:0]   degree;
+   wire [15:0]          mask;
+   wire [15:0]          len;
 
-   // Loopback implementation
-   wire   [15:0] tx_i, tx_q, rx_i, rx_q; // Internal transmit and receive data bus
+   setting_reg #(`FR_USER_0) sr_mode
+     ( .clock(clk_i),.reset(1'b0),.strobe(s_strobe_i),.addr(saddr_i),.in(sdata_i),
+       .out({loopback,receive,transmit,reset}) );
 
-   assign       tx_dac_i_o = loopback ? 16'b0 : tx_i;
-   assign       tx_dac_q_o = loopback ? 16'b0 : tx_q;
-   assign       rx_i = loopback ? tx_i : rx_adc_i_i;
-   assign       rx_q = loopback ? tx_q : rx_adc_q_i;
-   
-   setting_reg #(`FR_USER_0) sr_lfsr_degree
+   setting_reg #(`FR_USER_1) sr_lfsr_degree
      ( .clock(clk_i),.reset(1'b0),.strobe(s_strobe_i),.addr(saddr_i),.in(sdata_i),.out(degree) );
+   
+   lfsr_constants constants(.degree_i(degree),.mask_o(mask),.len_o(len));
 
-   setting_reg #(`FR_USER_1) sr_mode
-     ( .clock(clk_i),.reset(1'b0),.strobe(s_strobe_i),.addr(saddr_i),.in(sdata_i),
-       .out({loopback}) );
+   // Loopback implementation
+   wire [13:0] tx_i, tx_q;      
+   wire [15:0] tx_i_ext, tx_q_ext;
+   wire [15:0] rx_i, rx_q; 
 
-   lfsr_constants constants(.degree_i(degree),.mask_o(mask),.len_o(len));
+   sign_extend #(14,16) tx_i_extender(tx_i, tx_i_ext);
+   sign_extend #(14,16) tx_q_extender(tx_q, tx_q_ext);
 
+   assign tx_dac_i_o = loopback ? 14'b0 : tx_i;
+   assign tx_dac_q_o = loopback ? 14'b0 : tx_q;
+   assign rx_i       = loopback ? tx_i_ext : rx_adc_i_i;
+   assign rx_q       = loopback ? tx_q_ext : rx_adc_q_i;
+   
    sounder_tx transmitter
-     ( .clk_i(clk_i),.rst_i(tx_rst_i),.ena_i(tx_enable_i),.strobe_i(tx_strobe_i),.mask_i(mask),
+     ( .clk_i(clk_i),.rst_i(reset),.ena_i(transmit),
+       .strobe_i(tx_strobe_i),.mask_i(mask),
        .tx_i_o(tx_i),.tx_q_o(tx_q) );
    
    sounder_rx receiver
-     ( .clk_i(clk_i),.rst_i(rx_rst_i),.ena_i(rx_enable_i),
-       .rx_strobe_i(rx_strobe_i),.tx_strobe_i(tx_strobe_i),.mask_i(mask),.len_i(len),
+     ( .clk_i(clk_i),.rst_i(reset),.ena_i(receive),
+       .rx_strobe_i(rx_strobe_i),.tx_strobe_i(tx_strobe_i),.mask_i(mask),.degree_i(degree),.len_i(len),
        .rx_in_i_i(rx_i),.rx_in_q_i(rx_q),.rx_i_o(rx_imp_i_o),.rx_q_o(rx_imp_q_o),
-       .rx_strobe_o(rx_strobe_o) );
-   
+       .rx_strobe_o(rx_strobe_o),.loop_i(loopback));
+
 endmodule // sounder