Move retransmit sync logic to med_sync_control

Retransmit signals are produced with the RXI clock and were previously
synchronized to the TXI clock in tx_control, where the RXI clock is not
available. The incoming signals were sampled with the unrelated system
clock. Moving everything up one level allows for a cleaner CDC.

diff --git a/media_interfaces/sync/med_sync_control.vhd b/media_interfaces/sync/med_sync_control.vhd
index c91f378c82473187a84e3513d5acf071a6582bd7..6df14ad0658c2596ed33df0ad519e64e615f6bfb 100644 (file)
--- a/media_interfaces/sync/med_sync_control.vhd
+++ b/media_interfaces/sync/med_sync_control.vhd
@@ -70,6 +70,10 @@ signal request_retr_i     : std_logic;
 signal start_retr_i       : std_logic;
 signal request_retr_position_i  : std_logic_vector(7 downto 0);
 signal start_retr_position_i    : std_logic_vector(7 downto 0);
+signal request_retr_tx    : std_logic;
+signal start_retr_tx      : std_logic;
+signal request_retr_position_q  : std_logic_vector(7 downto 0);
+signal start_retr_position_q    : std_logic_vector(7 downto 0);
 signal rx_dlm_i           : std_logic;
 
 signal led_ok                 : std_logic;
@@ -237,11 +241,11 @@ THE_TX : tx_control
     TX_K_OUT               => TX_K,
     TX_CD_OUT              => TX_CD,
 
-    REQUEST_RETRANSMIT_IN  => request_retr_i,             --TODO
-    REQUEST_POSITION_IN    => request_retr_position_i,    --TODO
+    REQUEST_RETRANSMIT_IN  => request_retr_tx,            --TODO
+    REQUEST_POSITION_IN    => request_retr_position_q,    --TODO
 
-    START_RETRANSMIT_IN    => start_retr_i,               --TODO
-    START_POSITION_IN      => start_retr_position_i,      --TODO
+    START_RETRANSMIT_IN    => start_retr_tx,              --TODO
+    START_POSITION_IN      => start_retr_position_q,      --TODO
 
     SEND_DLM               => TX_DLM,
     SEND_DLM_WORD          => TX_DLM_WORD,
@@ -295,6 +299,38 @@ THE_RX_CONTROL : rx_control
 RX_DLM <= rx_dlm_i;
 MEDIA_MED2INT <= media_med2int_i;
 
+THE_RETRANSMIT_PULSE_SYNC_1 : pulse_sync
+port map(
+  CLK_A_IN        => CLK_RXI,
+  RESET_A_IN      => reset_i,
+  PULSE_A_IN      => request_retr_i,
+  CLK_B_IN        => CLK_TXI,
+  RESET_B_IN      => reset_i,
+  PULSE_B_OUT     => request_retr_tx
+);
+
+THE_RETRANSMIT_PULSE_SYNC_2 : pulse_sync
+port map(
+  CLK_A_IN        => CLK_RXI,
+  RESET_A_IN      => reset_i,
+  PULSE_A_IN      => start_retr_i,
+  CLK_B_IN        => CLK_TXI,
+  RESET_B_IN      => reset_i,
+  PULSE_B_OUT     => start_retr_tx
+);
+
+THE_POSITION_REG : process(CLK_RXI)
+begin
+  if rising_edge(CLK_RXI) then
+    if request_retr_i = '1' then
+      request_retr_position_q <= request_retr_position_i;
+    end if;
+    if start_retr_i = '1' then
+      start_retr_position_q <= start_retr_position_i;
+    end if;
+  end if;
+end process;
+
 -------------------------------------------------      
 -- Generate LED signals
 -------------------------------------------------   

diff --git a/media_interfaces/sync/tx_control.vhd b/media_interfaces/sync/tx_control.vhd
index 298e8d25167601d1cf12cedbea19a9545b207703..58d6d827345232210833856b813734bf61715e54 100644 (file)
--- a/media_interfaces/sync/tx_control.vhd
+++ b/media_interfaces/sync/tx_control.vhd
@@ -65,8 +65,6 @@ architecture arch of tx_control is
   signal ram_empty               : std_logic;
   signal ram_afull               : std_logic;
 
-  signal request_position_q      : std_logic_vector( 7 downto 0);
-  signal restart_position_q      : std_logic_vector( 7 downto 0);
   signal request_position_i      : std_logic_vector( 7 downto 0);
   signal restart_position_i      : std_logic_vector( 7 downto 0);
   signal make_request_i          : std_logic;
@@ -74,8 +72,6 @@ architecture arch of tx_control is
   signal load_read_pointer_i     : std_logic;
   signal send_dlm_in_i           : std_logic;
   signal send_dlm_i              : std_logic;
-  signal start_retransmit_i      : std_logic;
-  signal request_retransmit_i    : std_logic;
 
   signal buf_tx_read_out         : std_logic;
   signal tx_data_200             : std_logic_vector(17 downto 0);
@@ -374,26 +370,6 @@ begin
                                           D_OUT(0) => tx_allow_q);
 
 
-  THE_RETRANSMIT_PULSE_SYNC_1 : pulse_sync
-    port map(
-      CLK_A_IN        => CLK_100,
-      RESET_A_IN      => RESET_IN,
-      PULSE_A_IN      => REQUEST_RETRANSMIT_IN,
-      CLK_B_IN        => CLK_200,
-      RESET_B_IN      => RESET_IN,
-      PULSE_B_OUT     => request_retransmit_i
-    );
-
-  THE_RETRANSMIT_PULSE_SYNC_2 : pulse_sync
-    port map(
-      CLK_A_IN        => CLK_100,
-      RESET_A_IN      => RESET_IN,
-      PULSE_A_IN      => START_RETRANSMIT_IN,
-      CLK_B_IN        => CLK_200,
-      RESET_B_IN      => RESET_IN,
-      PULSE_B_OUT     => start_retransmit_i
-    );
-
 --   THE_RETRANSMIT_PULSE_SYNC_3 : pulse_sync
 --     port map(
 --       CLK_A_IN        => CLK_100,
@@ -405,18 +381,6 @@ begin
 --     );    
   send_dlm_in_i <= SEND_DLM;
     
-  THE_POSITION_REG : process(CLK_100)
-    begin
-      if rising_edge(CLK_100) then
-        if REQUEST_RETRANSMIT_IN = '1' then
-          request_position_q <= REQUEST_POSITION_IN;
-        end if;
-        if START_RETRANSMIT_IN = '1' then
-          restart_position_q <= START_POSITION_IN;
-        end if;
-      end if;
-    end process;
-
 
 --Store Request Retransmit position
   THE_STORE_REQUEST_PROC : process(CLK_200, RESET_IN)
@@ -428,9 +392,9 @@ begin
         if tx_allow_qtx = '0' then
           make_request_i     <= '0';
           request_position_i <= (others => '0');
-        elsif request_retransmit_i = '1' then
+        elsif REQUEST_RETRANSMIT_IN = '1' then
           make_request_i     <= '1';
-          request_position_i <= request_position_q;
+          request_position_i <= REQUEST_POSITION_IN;
         elsif current_state = SEND_REQUEST_L then
           make_request_i     <= '0';
         elsif current_state = SEND_REQUEST_H then
@@ -450,9 +414,9 @@ begin
         if tx_allow_qtx = '0' then
           make_restart_i         <= '0';
           restart_position_i     <= (others => '0');
-        elsif start_retransmit_i = '1' then
+        elsif START_RETRANSMIT_IN = '1' then
           make_restart_i         <= '1';
-          restart_position_i     <= restart_position_q;
+          restart_position_i     <= START_POSITION_IN;
         elsif current_state = SEND_START_L then
           make_restart_i         <= '0';
         elsif current_state = SEND_START_H then