Register inputs locally at this input to ease timing closure in case there are...

Register inputs locally at this input to ease timing closure in case there are multiple common_led_controller all using the same central source

libraries/base/common/src/vhdl/common_led_controller.vhd

@@ -29,9 +29,11 @@ USE common_lib.common_pkg.ALL;
 --   ctrl_on = '0' : then led = ctrl_input, so completely driven by external control
 --   ctrl_on = '1' : then led = '1' but pulses '0' for g_nof_ms each time that a ctrl_evt clk pulse occurs
 -- Remark:
---   The p_state machine ensures that after g_nof_ms off the led also stays on for at least g_nof_ms, to
---   avoid that a too fast ctrl_evt rate would cause the led too stay off. Hence the led can only accurately
---   visualize a certain ctrl_evt rate, faster events will get lost.
+--   The p_state machine ensures that after g_nof_ms off the led also stays on
+--   for at least g_nof_ms, to avoid that a too fast ctrl_evt rate would cause
+--   the led too stay off. Therefore the maximum event rate that can be
+--   signalled is 1/(2*g_nof_ms). If events occur faster then these can not be
+--   visualized exactly anymore and will get lost.
 
 ENTITY common_led_controller IS
   GENERIC (
@@ -40,7 +42,7 @@ ENTITY common_led_controller IS
   PORT (
     rst           : IN  STD_LOGIC;
     clk           : IN  STD_LOGIC;
-    pulse_ms          : IN  STD_LOGIC;         -- pulses every ms
+    pulse_ms      : IN  STD_LOGIC := '0';  -- pulses every ms, used to time the ctrl_evt effect on the led
     -- led control
     ctrl_on       : IN  STD_LOGIC := '0';
     ctrl_evt      : IN  STD_LOGIC := '0';  -- when ctrl_on='1' then the led output is on and pulses off for g_nof_ms when a ctrl_evt='1' event pulse occurs
@@ -58,6 +60,10 @@ ARCHITECTURE rtl OF common_led_controller IS
   SIGNAL state          : t_state;
   SIGNAL nxt_state      : t_state;
   
+  -- Register inputs locally at this input to ease timing closure in case there are multiple common_led_controller all using the same central source
+  SIGNAL pulse_ms_reg   : STD_LOGIC;
+  SIGNAL ctrl_input_reg : STD_LOGIC;
+  
   SIGNAL cnt            : NATURAL RANGE 0 TO g_nof_ms;
   SIGNAL nxt_cnt        : NATURAL;
   
@@ -68,23 +74,27 @@ BEGIN
   p_clk : PROCESS(rst, clk)
   BEGIN
     IF rst='1' THEN
+      pulse_ms_reg   <= '0';
+      ctrl_input_reg <= '0';
       cnt            <= 0;
       state          <= s_idle;
       led            <= '0';
     ELSIF rising_edge(clk) THEN
+      pulse_ms_reg   <= pulse_ms;
+      ctrl_input_reg <= ctrl_input;
       cnt            <= nxt_cnt;
       state          <= nxt_state;
       led            <= nxt_led;
     END IF;
   END PROCESS;
   
-  p_state : PROCESS(state, ctrl_on, ctrl_evt, ctrl_input, pulse_ms, cnt)
+  p_state : PROCESS(state, ctrl_on, ctrl_evt, ctrl_input_reg, pulse_ms_reg, cnt)
   BEGIN
     IF ctrl_on='0' THEN
       -- Default behaviour when ctrl_on = '0'
       nxt_cnt   <= 0;
       nxt_state <= s_idle;
-      nxt_led   <= ctrl_input;
+      nxt_led   <= ctrl_input_reg;
     ELSE
       -- Pulse led off briefly on event when ctrl_on = '1'
       nxt_cnt   <= cnt;
@@ -98,7 +108,7 @@ BEGIN
           END IF;
         WHEN s_off =>
           nxt_led <= '0';
-          IF pulse_ms='1' THEN
+          IF pulse_ms_reg='1' THEN
             nxt_cnt <= cnt+1;
             IF cnt=g_nof_ms THEN
               nxt_cnt <= 0;
@@ -106,7 +116,7 @@ BEGIN
             END IF;
           END IF;
         WHEN OTHERS =>  -- s_on
-          IF pulse_ms='1' THEN
+          IF pulse_ms_reg='1' THEN
             nxt_cnt <= cnt+1;
             IF cnt=g_nof_ms THEN
               nxt_cnt <= 0;