Eth: transmitter model

imihajlow · Oct 24, 2023 · fa30839 · fa30839
1 parent 4aaf5be
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Showing 4 changed files with 35 additions and 13 deletions.
diff --git a/doc/waveforms/eth/tx-begin.js b/doc/waveforms/eth/tx-begin.js
@@ -9,7 +9,7 @@
   {name: "tx_shift_q7", wave: "0..2.2.2.2.2.2.2.2.2.2.2.2.2.2.", data: "x.0 x.1 x.2 x.3 x.4 x.5 x.6 x.7 b0.0 b0.1 b0.2 b0.3 b0.4 b0.5"},
   {name: "tx_buf_d", wave: "x..........2...............2...", data: "b0 b1"},
   {name: "n_tx_shift_pl", wave: "1..01..............01.........."},
-  {name: "tx_shift_cp", wave: "0..1010101010101010101010101010"},
+  {name: "tx_shift_cp", wave: "1...010101010101010101010101010"},
   {name: "tx_byte_cnt", wave: "x..2...............2...........", data: "0 1"},
   {name: "tx_cnt", wave: "x..2222222222222222222222222222", data: "0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 0 1 2 3 4 5 6 7 8 9 10 11"},
 ],

diff --git a/doc/waveforms/eth/tx-end.js b/doc/waveforms/eth/tx-end.js
@@ -1,14 +1,16 @@
 /* https://wavedrom.com/editor.html */
 {signal: [
-  {name: "n_tx_hold", wave: "1..............0..."},
-  {name: "tx_cp_in", wave: "p..................", period: 0.5},
-  {name: "tx_sck", wave: "1010101010101010..."},
-  {name: "tx_mosi", wave: "2.2.2.2.2.2.2.2.0..", data: "b1023.0 b1023.1 b1023.2 b1023.3 b1023.4 b1023.5 b1023.6 b1023.7"},
-  {name: "tx_shift_q7", wave: "22.2.2.2.2.2.2.0...", data: "..23.0 b1023.1 b1023.2 b1023.3 b1023.4 b1023.5 b1023.6 b1023.7"},
-  {name: "n_tx_shift_pl", wave: "1..............0..."},
-  {name: "tx_shift_cp", wave: "010101010101010...."},
-  {name: "tx_byte_cnt", wave: "2..............2...", data: "1023 0"},
-  {name: "tx_cnt", wave: "2222222222222222...", data: "1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 0"},
+  {name: "n_tx_hold", wave: "1..................0..."},
+  {name: "tx_cp_in", wave: "p......................", period: 0.5},
+  {name: "tx_oe", wave: "1.................0...."},
+  {name: "tx_sck", wave: "101010101010101010....."},
+  {name: "tx_mosi", wave: "2.2.2.2.2.2.2.2.2.0....", data: "b1022.7 b1023.0 b1023.1 b1023.2 b1023.3 b1023.4 b1023.5 b1023.6 b1023.7"},
+  {name: "tx_shift_q7", wave: "22.2.2.2.2.2.2.2.0.....", data: "..22.7 b1023.0 b1023.1 b1023.2 b1023.3 b1023.4 b1023.5 b1023.6 b1023.7"},
+  {name: "tx_buf_d", wave: "2........2.............", data: "b1023 b0"},
+  {name: "n_tx_shift_pl", wave: "101..............01...."},
+  {name: "tx_shift_cp", wave: "010101010101010101....."},
+  {name: "tx_byte_cnt", wave: "2x...2...........2.....", data: "1023 1024 0"},
+  {name: "tx_cnt", wave: "222222222222222222.....", data: "15 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 0 1 2 3 4 5 6 7 8 9 10 11"},
 ],
   foot: {text:"Frame transmission end"},
   config: {hscale: 1},

diff --git a/model/eth/test/test_transmitter.v b/model/eth/test/test_transmitter.v
@@ -94,10 +94,19 @@ module test_transmitter();
                 $display("recv failed: expected %0h, got %0h", expected_data, x);
                 #5
                 $fatal;
+            end else begin
+                // $display("recv %0h ok", x);
             end
         end
     endtask
 
+    function [7:0] get_tx_data;
+        input [15:0] addr;
+        begin
+            get_tx_data =  (addr[7:0] + 16'd1) * 16'd239 + addr[9:2] * 16'd113;
+        end
+    endfunction
+
     initial begin
         $dumpfile("test_transmitter.vcd");
         $dumpvars;
@@ -133,23 +142,34 @@ module test_transmitter();
         n_rst = 1'b1;
         #101
         for (i = 16'hf000; i != 16'hf400; i = i + 1) begin
-            write(i[15:0], i[7:0]);
+            write(i[15:0], get_tx_data(i[15:0]));
         end
         write(TX_RST_ADDR, 8'b0);
     end
 
 
     integer j;
+    reg wait_for_extra_sck;
     initial begin
         wait(~n_rst);
         wait(n_rst);
         #50
         for (j = 0; j != 1024; j = j + 1) begin
-            recv_and_check(j[7:0]);
+            recv_and_check(get_tx_data(j[15:0]));
         end
+        wait_for_extra_sck = 1'b1;
+        #50000
         $finish;
     end
 
+    initial begin
+        wait_for_extra_sck = 1'b0;
+        wait(wait_for_extra_sck);
+        wait(tx_sck);
+        $display("unexpected sck transition after receiving all data");
+        $fatal;
+    end
+
     initial begin
         #2500000
         $display("timeout");

diff --git a/model/eth/transmitter.v b/model/eth/transmitter.v
@@ -142,7 +142,7 @@ module eth_transmitter(
     assign #10 n_tx_buf_we = n_a_buf_sel | n_we;
     assign tx_a_sel = n_tx_buf_we;
 
-    wire #10 n_tx_hold_set = n_rst & ~tx_byte_cnt[10];
+    wire #10 n_tx_hold_set = n_rst & ~(tx_byte_cnt[10] & n_tx_byte_clk);
     d_ff_7474 ff_hold(
         .q(tx_hold),
         .n_q(n_tx_hold),