L2SDP-78: add some tests for offset_cnt to the testbench

libraries/io/ppsh/tb/vhdl/tb_mms_ppsh.vhd

@@ -52,6 +52,8 @@ ARCHITECTURE tb OF tb_mms_ppsh IS
   SIGNAL pps_toggle       : STD_LOGIC;
   SIGNAL pps_stable       : STD_LOGIC;
   SIGNAL capture_cnt      : NATURAL;
+  SIGNAL offset_cnt       : NATURAL;
+  SIGNAL last_offset_cnt  : NATURAL;
 
 BEGIN
 
@@ -99,6 +101,7 @@ BEGIN
                                                  -- expected_cnt = c_pps_period = 1000
     proc_mem_mm_bus_wr(1, v_word, clk, reg_mosi);
 
+
     -- Simulate reading PPS status every 10 PPS periods
     proc_common_wait_some_cycles(clk, 10);
     FOR I IN 0 TO 9 LOOP
@@ -111,6 +114,16 @@ BEGIN
       capture_cnt <= TO_UINT(reg_miso.rddata(ceil_log2(c_clk_freq)-1 DOWNTO 0));
     END LOOP;
 
+    -- Simulate reading PPS offset counter every 0.1 PPS periods
+    proc_common_wait_some_cycles(clk, 10);
+    FOR I IN 0 TO 4 LOOP
+      proc_common_wait_some_cycles(clk, c_pps_period/10);
+      last_offset_cnt <= offset_cnt;
+      proc_mem_mm_bus_rd(2, clk, reg_mosi);
+      proc_common_wait_some_cycles(clk, 1);
+      offset_cnt <= TO_UINT(reg_miso.rddata(ceil_log2(c_clk_freq)-1 DOWNTO 0));
+    END LOOP;
+
     proc_common_wait_some_cycles(clk, 100);
     tb_end <= '1';
     WAIT;
@@ -158,6 +171,12 @@ BEGIN
     proc_common_wait_some_cycles(clk, c_pps_period*10);
     ASSERT pps_stable='1'   REPORT "9) Wrong pps_stable" SEVERITY ERROR;
     ASSERT capture_cnt=1000 REPORT "9) Wrong capture_cnt" SEVERITY ERROR;
+    -- 10
+    proc_common_wait_some_cycles(clk, c_pps_period/10);
+    ASSERT offset_cnt=last_offset_cnt REPORT "10) Wrong offset_cnt" SEVERITY ERROR;
+    -- 11
+    proc_common_wait_some_cycles(clk, c_pps_period/10);
+    ASSERT offset_cnt=last_offset_cnt REPORT "11) Wrong offset_cnt" SEVERITY ERROR;
     WAIT;
   END PROCESS;
 

libraries/io/ppsh/tb/vhdl/tb_ppsh.vhd

@@ -243,6 +243,22 @@ BEGIN
           REPORT "PPSH : Unexpected capture count value at 49 s." SEVERITY ERROR;
         END IF;
       END IF;
+
+      -- check if offset_cnt is counting
+      IF (NOW > 7500 ms) AND (NOW <= 7500 ms + c_clk_period) THEN
+        --REPORT "PPSH : offset_cnt = " & integer'image(To_integer(unsigned(offset_cnt))) SEVERITY ERROR;
+        IF UNSIGNED(offset_cnt)/=475 THEN
+          REPORT "PPSH : Unexpected offset count value at 5.5 s." SEVERITY ERROR;
+        END IF;
+      END IF;
+
+      IF (NOW > 7700 ms) AND (NOW <= 7700 ms + c_clk_period) THEN
+        --REPORT "PPSH : offset_cnt = " & integer'image(To_integer(unsigned(offset_cnt))) SEVERITY ERROR;
+        IF UNSIGNED(offset_cnt)/=675 THEN
+          REPORT "PPSH : Unexpected offset count value at 5.5 s." SEVERITY ERROR;
+        END IF;
+      END IF;
+
     END IF;
   END PROCESS;