[wrpc testbench] bugfix: the testbench did not detect situation where

no frames are transmitted/received, it only checked correctness of transmission added timeout to throw an error when no frames is received for an unacceptable time

[wrpc testbench] bugfix: the testbench did not detect situation where
no frames are transmitted/received, it only checked correctness of transmission added timeout to throw an error when no frames is received for an unacceptable time
ac058007 · Maciej Lipinski · 38f77982 · ac058007
Commit ac058007 authored Dec 14, 2017 by Maciej Lipinski
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Showing with 35 additions and 6 deletions

main.sv testbench/wrc_core/main.sv +35 -6

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--- a/testbench/wrc_core/main.sv
+++ b/testbench/wrc_core/main.sv
@@ -151,6 +151,11 @@ module main;
  wire wrc_snk_stall;
  wire wrc_snk_err;
  wire link_up;
+  // globa variables for "tiemout" in case the transmitted frames are not received
+  int rx_sth   = 0;
+  int tx_sth   = 0;
+  int wait_cnt = 0;
+  int rx_cnt   = 0;

  /// ////////////////////// WR PTP CORE /////////////////////////////////////
  wr_core #(
@@ -388,12 +393,18 @@ module main;
    tx_sizes = {};

    #1400us;
+    
+    tx_sth = 1; // indicate that transmitting frames
    $display("Fixed IFG");
    send_frames(ep_src, frame_number, 1 /* force Inter-frame gap of 1 us */);
    $display("Random IFG");
    send_frames(ep_src, frame_number, 0 /* random Inter-frame gap, between 1 and 100us */);

-
+    while (rx_cnt<(frame_number+frame_number)) #1us; 
+    tx_sth = 0; //after having received all the frames, indicate that no frames 
+                //are being transmitted, i.e. betweeen tx and rx
+    #100us;
+    $finish; //finish 
  end

  initial begin /// receive frames from WRPC (looped back or sent by LM32), loopback frames
@@ -433,11 +444,12 @@ module main;
    acc_lbk.write(`ADDR_LBK_MCR, `LBK_MCR_ENA);
    wait(link_up == 1'b1);
    #1200us;
-
+    
    while(1) begin
      #0.5us;
+      rx_sth=0;//indicate that nothing is being received
      ep_snk.recv(pkt);
-
+      rx_sth=1; // indicate that you are handling received frame
      /// /////////////////////////////////////////////////////////////////////////////////
      /// received frame generated inside LM32
      if(pkt.dst == PTP_MAC) begin
@@ -469,7 +481,7 @@ module main;
      else if(pkt.dst == SELF_MAC) begin // simulation-generated tests
        self_seqID_rx = 'hFFFFFFFF & (pkt.payload[3] << 24 |pkt.payload[2] << 16 | pkt.payload[1] << 8 | pkt.payload[0]);
        $display("--> recv [size=%4d]: simulation-generated frame that is looped back to the simulation sink, seqID: exp=%4d | rx=%4d",pkt.size, self_seqID_reg, self_seqID_rx);
-
+        rx_cnt++;
        if(self_seqID_reg != self_seqID_rx)
          $warning("simulation-generated ERROR: wrong seqID");
        self_seqID_reg = self_seqID_rx +1;
@@ -490,8 +502,25 @@ module main;
        acc_lbk.read(`ADDR_LBK_FWD_CNT, val64);
        $display("fwd_cnt: %d", val64);
      end
-      total_cnt++;
+      total_cnt++; // count received frames that are sent by simulation
    end
  end
-
+ 
+  /// very simply timout mechanism verify that we receive frames when they are
+  /// sent within a timeout
+  /// We count how long frames are not received when they are sent. if this 
+  /// is too long, timeout
+  initial begin 
+    while(1) begin
+      #0.5us;
+      if (wait_cnt > 2000) begin // this is too much waiting, error
+         $warning("ERROR: RX TIMEOUT, no frame was received within expected timeout");
+         $finish;
+      end
+      else if(rx_sth==0 & tx_sth == 1) // if transmission ongoing and nothing received, count
+        wait_cnt++;
+      else 
+        wait_cnt=0; //if transmitted and recieved, OK
+      end
+    end
 endmodule // main