wr_endpoint: fix sof detection in tx_framer

Under higher load of traffic SOF was being detected while main FSM was not yet done with sending frame. That caused OOB FSM to reset and "tx timestamp never became available" warnings in WR PTP Core software.

wr_endpoint: fix sof detection in tx_framer
Under higher load of traffic SOF was being detected while main FSM was not yet done with sending frame. That caused OOB FSM to reset and "tx timestamp never became available" warnings in WR PTP Core software.
3fbaa93c · Grzegorz Daniluk · Tomasz Wlostowski · 68c399cd · 3fbaa93c
Commit 3fbaa93c authored Mar 10, 2014 by Grzegorz Daniluk Committed by Tomasz Wlostowski Mar 19, 2014
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ep_tx_framer.vhd modules/wr_endpoint/ep_tx_framer.vhd +18 -1

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--- a/modules/wr_endpoint/ep_tx_framer.vhd
+++ b/modules/wr_endpoint/ep_tx_framer.vhd
@@ -155,6 +155,7 @@ architecture behavioral of ep_tx_framer is
  signal snk_valid : std_logic;

  signal sof_p1, eof_p1, abort_p1, error_p1 : std_logic;
+  signal sof_reg  : std_logic;
  signal snk_cyc_d0                         : std_logic;

  signal decoded_status : t_wrf_status_reg;
@@ -274,7 +275,23 @@ begin  -- behavioral
    end if;
  end process;

-  sof_p1    <= not snk_cyc_d0 and snk_i.cyc;
+  gen_sof: process(clk_sys_i)
+  begin
+    if rising_edge(clk_sys_i) then
+      if (rst_n_i = '0') then
+        sof_reg <= '0';
+      else
+        if (snk_cyc_d0 = '0' and snk_i.cyc = '1' and state /= TXF_IDLE) then
+          sof_reg <= '1';
+        elsif(state = TXF_IDLE and pcs_dreq_i = '1') then
+          sof_reg <= '0';
+        end if;
+      end if;
+    end if;
+  end process;
+
+  sof_p1    <= (not snk_cyc_d0 and snk_i.cyc) or sof_reg when (state = TXF_IDLE and pcs_dreq_i = '1')
+               else '0';
  eof_p1    <= snk_cyc_d0 and not snk_i.cyc;
  snk_valid <= (snk_i.cyc and snk_i.stb and snk_i.we) and not stall_int;