Simulate multiple in_sync intervals to show output pfs_sync.

applications/lofar1/pfs/tb/vhdl/tb_pfs.vhd

@@ -69,7 +69,15 @@ BEGIN
     in_dat_x <= TO_UVEC(0, in_dat_x'LENGTH);
     WAIT FOR 1 us;
     WAIT UNTIL rising_edge(clk);
+    -- LOFAR1 sync is active one clk cycle before sync interval
+    -- create sync for first sync interval
+    in_sync <= '1';
+    WAIT UNTIL rising_edge(clk);
+    in_sync <= '0';
     in_val <= '1';
+    FOR k IN 1 TO 2 LOOP
+    
+      -- issue impulse
       FOR j IN 1 TO 16 LOOP
         FOR i IN 1 TO 1024 LOOP
           IF j = 1 THEN
@@ -80,8 +88,15 @@ BEGIN
           WAIT UNTIL rising_edge(clk);
         END LOOP;
       END LOOP;
-    -- continue some more
-    proc_common_wait_some_cycles(clk, 1024*4);
+      
+      -- continue some more per sync interval
+      proc_common_wait_some_cycles(clk, 1024*4-1);  -- -1 to create sync for next sync interval
+      in_sync <= '1';
+      WAIT UNTIL rising_edge(clk);
+      in_sync <= '0';
+    END LOOP;
+    -- continue some more to observe last pfs_sync
+    proc_common_wait_some_cycles(clk, 1024*1);      
     tb_end <= '1';
     WAIT;
   END PROCESS;