added clipping function to common_counter

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

@@ -22,6 +22,7 @@
 -- Purpose : Counter with extra options
 -- Description:
 --   - default wrap at 2**g_width or special wrap at fixed g_max or dynamically via cnt_max
+--   - count can be clipped instead of wrapped by setting g_clip to True.
 --   - default increment +1 or other g_step_size
 --   - external clr
 --   - external load with g_init or dynamically via load
@@ -42,7 +43,8 @@ ENTITY common_counter IS
     g_init      : INTEGER := 0;
     g_width     : NATURAL := 32;
     g_max       : NATURAL := 0;  -- default 0 to disable the g_max setting. 
-    g_step_size : INTEGER := 1   -- counting in steps of g_step_size, can be + or -
+    g_step_size : INTEGER := 1;  -- counting in steps of g_step_size, can be + or -
+    g_clip      : BOOLEAN := FALSE -- when True, counter will clip at g_max, if g_max = 0 and g_step_size > 0, the counter clips at 2**g_width -1.
   );
   PORT (
     rst     : IN  STD_LOGIC := '0';    -- either use asynchronous rst or synchronous cnt_clr
@@ -51,7 +53,8 @@ ENTITY common_counter IS
     cnt_clr : IN  STD_LOGIC := '0';    -- synchronous cnt_clr is only interpreted when clken is active
     cnt_ld  : IN  STD_LOGIC := '0';    -- cnt_ld loads the output count with the input load value, independent of cnt_en
     cnt_en  : IN  STD_LOGIC := '1';
-    cnt_max : IN  STD_LOGIC_VECTOR(g_width-1 DOWNTO 0) := TO_UVEC(sel_a_b(ceil_log2(g_max+1)>g_width, 0, g_max),  g_width);  -- see remarks
+    cnt_max : IN  STD_LOGIC_VECTOR(g_width-1 DOWNTO 0) := sel_a_b( g_step_size > 0 AND g_max = 0, array_init('1', g_width), 
+                                                          sel_a_b( ceil_log2(g_max+1) > g_width,  array_init('1', g_width), TO_UVEC(g_max, g_width) ));  -- see remarks
     load    : IN  STD_LOGIC_VECTOR(g_width-1 DOWNTO 0) := TO_SVEC(g_init, g_width);
     count   : OUT STD_LOGIC_VECTOR(g_width-1 DOWNTO 0)
   );
@@ -60,7 +63,6 @@ END common_counter;
 
 ARCHITECTURE rtl OF common_counter IS
    
-  CONSTANT zeros    : STD_LOGIC_VECTOR(count'RANGE) := (OTHERS => '0');           -- used to check if cnt_max is zero
   SIGNAL reg_count  : STD_LOGIC_VECTOR(count'RANGE) := TO_SVEC(g_init, g_width);  -- in case rst is not used
   SIGNAL nxt_count  : STD_LOGIC_VECTOR(count'RANGE) := TO_SVEC(g_init, g_width);  -- to avoid Warning: NUMERIC_STD.">=": metavalue detected, returning FALSE, when using unsigned()
   SIGNAL comb_count : STD_LOGIC_VECTOR(count'RANGE) := TO_SVEC(g_init, g_width);  -- to avoid Warning: NUMERIC_STD.">=": metavalue detected, returning FALSE, when using unsigned()
@@ -87,8 +89,12 @@ BEGIN
   p_count : PROCESS(reg_count, cnt_clr, cnt_en, cnt_ld, load, cnt_max)
   BEGIN
     nxt_count <= reg_count;
-    IF cnt_clr='1' OR (reg_count=cnt_max AND cnt_max /= zeros) THEN
+    IF cnt_clr='1' THEN
       nxt_count <= (OTHERS => '0');
+    ELSIF reg_count=cnt_max THEN
+      IF NOT g_clip THEN
+        nxt_count <= (OTHERS => '0');
+      END IF;
     ELSIF cnt_ld='1' THEN
       nxt_count <= load;
     ELSIF cnt_en='1' THEN

libraries/base/dp/src/vhdl/dp_block_validate_bsn_at_sync.vhd

@@ -134,7 +134,8 @@ BEGIN
   cnt_discarded_en <= '1' WHEN in_sosi.sync = '1' AND bsn_ok = '0' ELSE '0';
   u_discarded_counter : ENTITY common_lib.common_counter
   GENERIC MAP (
-    g_width => c_word_w
+    g_width => c_word_w,
+    g_clip  => TRUE
   )
   PORT MAP ( 
     rst => dp_rst,
@@ -148,7 +149,8 @@ BEGIN
   -- sync counter
   u_blk_counter : ENTITY common_lib.common_counter
   GENERIC MAP (
-    g_width => c_word_w
+    g_width => c_word_w,
+    g_clip  => TRUE
   )
   PORT MAP ( 
     rst => dp_rst,

libraries/base/dp/src/vhdl/dp_block_validate_err.vhd

@@ -120,7 +120,6 @@ ARCHITECTURE rtl OF dp_block_validate_err IS
   SIGNAL mm_cnt_clr       : STD_LOGIC;
   SIGNAL cnt_clr          : STD_LOGIC;
   SIGNAL cnt_blk          : STD_LOGIC_VECTOR(g_cnt_w-1 DOWNTO 0);
-  SIGNAL cnt_blk_en       : STD_LOGIC;
   SIGNAL cnt_discarded    : STD_LOGIC_VECTOR(g_cnt_w-1 DOWNTO 0);
   SIGNAL cnt_discarded_en : STD_LOGIC;
   SIGNAL cnt_err          : t_cnt_err_arr(g_nof_err_counts-1 DOWNTO 0);
@@ -151,26 +150,26 @@ BEGIN
     );
 
   -- block counter
-  cnt_blk_en <= snk_in.eop WHEN UNSIGNED(cnt_blk) < UNSIGNED(c_max_cnt) ELSE '0';
   u_blk_counter : ENTITY common_lib.common_counter
   GENERIC MAP (
-    g_width => g_cnt_w
+    g_width => g_cnt_w,
+    g_clip  => TRUE
   )
   PORT MAP ( 
     rst => dp_rst,
     clk => dp_clk,
 
     cnt_clr => cnt_clr, 
-    cnt_en  => cnt_blk_en,
+    cnt_en  => snk_in.eop,
     count   => cnt_blk
   );
 
   -- discarded block counter
-  cnt_discarded_en <= '1' WHEN snk_in.eop = '1' AND TO_UINT(snk_in.err(g_nof_err_counts-1 DOWNTO 0)) > 0 
-                                                AND UNSIGNED(cnt_discarded) < UNSIGNED(c_max_cnt) ELSE '0';
+  cnt_discarded_en <= snk_in.eop WHEN TO_UINT(snk_in.err(g_nof_err_counts-1 DOWNTO 0)) > 0 ELSE '0';
   u_discarded_counter : ENTITY common_lib.common_counter
   GENERIC MAP (
-    g_width => g_cnt_w
+    g_width => g_cnt_w,
+    g_clip  => TRUE
   )
   PORT MAP ( 
     rst => dp_rst,
@@ -183,10 +182,11 @@ BEGIN
 
   -- error counters
   gen_err_counters : FOR I IN 0 TO g_nof_err_counts-1 GENERATE
-    cnt_err_en(I) <= snk_in.eop AND snk_in.err(I) WHEN UNSIGNED(cnt_err(I)) < UNSIGNED(c_max_cnt) ELSE '0';
+    cnt_err_en(I) <= snk_in.eop AND snk_in.err(I);
     u_blk_counter : ENTITY common_lib.common_counter
     GENERIC MAP (
-      g_width => g_cnt_w
+      g_width => g_cnt_w,
+      g_clip  => TRUE
     )
     PORT MAP ( 
       rst => dp_rst,