diff --git a/libraries/base/diag/src/vhdl/diag_rx_seq.vhd b/libraries/base/diag/src/vhdl/diag_rx_seq.vhd
index 33d721703386bc51e167f3f4ac40b63ad0b79814..68c38ef3a650077008e551e9051c94a10338686e 100644
--- a/libraries/base/diag/src/vhdl/diag_rx_seq.vhd
+++ b/libraries/base/diag/src/vhdl/diag_rx_seq.vhd
@@ -52,6 +52,7 @@ ENTITY diag_rx_seq IS
   GENERIC (
     g_input_reg  : BOOLEAN := FALSE;  -- Use unregistered input to save logic, use registered input to ease achieving timing constrains.
     g_sel        : STD_LOGIC := '1';  -- '0' = PRSG, '1' = COUNTER
+    g_cnt_w      : NATURAL := c_word_w;
     g_dat_w      : NATURAL := 12;
     g_diag_res_w : NATURAL := 16
   );
@@ -67,7 +68,8 @@ ENTITY diag_rx_seq IS
     diag_res_val : OUT STD_LOGIC;
     
     -- ST input
-    in_dat       : IN  STD_LOGIC_VECTOR(g_dat_w-1 DOWNTO 0);
+    in_cnt       : OUT STD_LOGIC_VECTOR(g_cnt_w-1 DOWNTO 0);  -- count valid input test sequence data
+    in_dat       : IN  STD_LOGIC_VECTOR(g_dat_w-1 DOWNTO 0);  -- input test sequence data
     in_val       : IN  STD_LOGIC    -- gaps are allowed, however diag_res requires at least 2 valid in_dat to report a valid result
   );
 END diag_rx_seq;
@@ -280,4 +282,21 @@ BEGIN
     END IF;
   END PROCESS;
   
+  
+  ------------------------------------------------------------------------------
+  -- Count number of valid input data
+  ------------------------------------------------------------------------------
+  u_common_counter : ENTITY common_lib.common_counter
+  GENERIC MAP (
+    g_latency   => 1,  -- default 1 for registered count output, use 0 for immediate combinatorial count output
+    g_width     => g_cnt_w
+  )
+  PORT MAP (
+    rst     => rst,
+    clk     => clk,
+    clken   => clken,
+    cnt_clr => diag_dis,    -- synchronous cnt_clr is only interpreted when clken is active
+    cnt_en  => in_val,
+    count   => in_cnt
+  );
 END rtl;
diff --git a/libraries/base/diag/src/vhdl/diag_tx_seq.vhd b/libraries/base/diag/src/vhdl/diag_tx_seq.vhd
index cd084b02482166053072c4b3090c41162eebf1c5..99ee6d584a60452495c15af254aa75fd772f9cc6 100644
--- a/libraries/base/diag/src/vhdl/diag_tx_seq.vhd
+++ b/libraries/base/diag/src/vhdl/diag_tx_seq.vhd
@@ -39,6 +39,7 @@ ENTITY diag_tx_seq IS
   GENERIC (
     g_sel      : STD_LOGIC := '1';  -- '0' = PRSG, '1' = COUNTER
     g_init     : NATURAL := 0;      -- init value for out_dat when diag_en = '0'
+    g_cnt_w    : NATURAL := c_word_w;
     g_dat_w    : NATURAL            -- >= 1, test data width
   );
   PORT (
@@ -51,7 +52,8 @@ ENTITY diag_tx_seq IS
     diag_dat   : IN  STD_LOGIC_VECTOR(g_dat_w-1 DOWNTO 0) := TO_UVEC(g_init, g_dat_w);  -- init value for out_dat when diag_en = '0'
     -- ST output
     diag_req   : IN  STD_LOGIC := '1';   -- '1' = request output, '0' = halt output
-    out_dat    : OUT STD_LOGIC_VECTOR(g_dat_w-1 DOWNTO 0);  -- test sequence data
+    out_cnt    : OUT STD_LOGIC_VECTOR(g_cnt_w-1 DOWNTO 0);  -- count valid output test sequence data
+    out_dat    : OUT STD_LOGIC_VECTOR(g_dat_w-1 DOWNTO 0);  -- output test sequence data
     out_val    : OUT STD_LOGIC                              -- '1' when out_dat is valid
   );
 END diag_tx_seq;
@@ -61,6 +63,8 @@ ARCHITECTURE rtl OF diag_tx_seq IS
 
   CONSTANT c_lfsr_nr     : NATURAL := g_dat_w - c_common_lfsr_first;
   
+  SIGNAL diag_dis        : STD_LOGIC;
+  
   SIGNAL prsg            : STD_LOGIC_VECTOR(out_dat'RANGE);
   SIGNAL nxt_prsg        : STD_LOGIC_VECTOR(out_dat'RANGE);
   SIGNAL cntr            : STD_LOGIC_VECTOR(out_dat'RANGE);
@@ -71,6 +75,8 @@ ARCHITECTURE rtl OF diag_tx_seq IS
 
 BEGIN
 
+  diag_dis <= NOT diag_en;
+  
   p_clk : PROCESS (rst, clk)
   BEGIN
     IF rst='1' THEN
@@ -100,4 +106,19 @@ BEGIN
   nxt_out_dat <= prsg WHEN diag_sel='0' ELSE cntr;
   nxt_out_val <= diag_en AND diag_req;  -- 'en' for entire test on/off, 'req' for dynamic invalid gaps in the stream
   
+  -- Count number of valid output data
+  u_common_counter : ENTITY common_lib.common_counter
+  GENERIC MAP (
+    g_latency   => 1,  -- default 1 for registered count output, use 0 for immediate combinatorial count output
+    g_width     => g_cnt_w
+  )
+  PORT MAP (
+    rst     => rst,
+    clk     => clk,
+    clken   => clken,
+    cnt_clr => diag_dis,    -- synchronous cnt_clr is only interpreted when clken is active
+    cnt_en  => nxt_out_val,
+    count   => out_cnt
+  );
+  
 END rtl;