-Cleaned code.

libraries/dsp/st/tb/vhdl/tb_st_histogram.vhd

@@ -80,10 +80,9 @@ ARCHITECTURE tb OF tb_st_histogram IS
   -- Constants derived from generics
   ---------------------------------------------------------------------------
   CONSTANT c_expected_ram_content_counter : NATURAL := g_nof_data_per_sync/g_nof_bins;
-  CONSTANT c_nof_levels_per_bin : NATURAL := (2**g_data_w)/g_nof_bins; --e.g. 2 values per bin if g_data_w=9 (512 levels) and g_nof_bins=256
-
-  CONSTANT c_ram_dat_w : NATURAL := ceil_log2(g_nof_data_per_sync)+1;
-  CONSTANT c_ram_adr_w : NATURAL := ceil_log2(g_nof_bins);
+  CONSTANT c_nof_levels_per_bin           : NATURAL := (2**g_data_w)/g_nof_bins; --e.g. 2 values per bin if g_data_w=9 (512 levels) and g_nof_bins=256
+  CONSTANT c_ram_dat_w                    : NATURAL := ceil_log2(g_nof_data_per_sync)+1;
+  CONSTANT c_ram_adr_w                    : NATURAL := ceil_log2(g_nof_bins);
     
   ---------------------------------------------------------------------------
   -- Clocks and resets
@@ -98,21 +97,20 @@ ARCHITECTURE tb OF tb_st_histogram IS
   ----------------------------------------------------------------------------
   -- stimuli
   ----------------------------------------------------------------------------
-  CONSTANT c_sine_amplitude               : REAL := real((2**g_data_w)/2-1);
+  CONSTANT c_sine_amplitude              : REAL := real((2**g_data_w)/2-1);
   CONSTANT c_sine_nof_periods            : REAL := 1.0;
   CONSTANT c_sine_nof_samples_per_period : REAL := real(g_nof_data_per_sync)/c_sine_nof_periods;
   CONSTANT c_sine_time_step_denom        : REAL := sel_a_b(g_lock_sine, MATH_2_PI, 5.0); -- Use 5 instead of 2 pi to create unlocked, drifting sine wave
   CONSTANT c_sine_time_step              : REAL := c_sine_time_step_denom / c_sine_nof_samples_per_period;
 
-  SIGNAL stimuli_en : STD_LOGIC := '1';
-
-  SIGNAL stimuli_src_out : t_dp_sosi;
+  SIGNAL stimuli_en          : STD_LOGIC := '1';
+  SIGNAL stimuli_src_out     : t_dp_sosi;
   SIGNAL nxt_stimuli_src_out : t_dp_sosi;
-  SIGNAL stimuli_src_in  : t_dp_siso;
-  SIGNAL stimuli_count   : REAL;
-  SIGNAL stimuli_data    : STD_LOGIC_VECTOR(g_data_w-1 DOWNTO 0); --NOTE This is undefined in the wave window
-
-  SIGNAL stimuli_done    : STD_LOGIC;
+  SIGNAL stimuli_src_in      : t_dp_siso;
+  SIGNAL stimuli_count       : REAL;
+  SIGNAL stimuli_data        : STD_LOGIC_VECTOR(g_data_w-1 DOWNTO 0); -- QuestaSim: Format->Analog, Radix->Decimal
+  SIGNAL random_data         : STD_LOGIC_VECTOR(g_data_w-1 DOWNTO 0);
+  SIGNAL stimuli_done        : STD_LOGIC;
 
   ----------------------------------------------------------------------------
   -- st_histogram
@@ -131,8 +129,8 @@ ARCHITECTURE tb OF tb_st_histogram IS
   SIGNAL histogram_bin_signed   : INTEGER; -- QuestaSim: Radix->Decimal
   SIGNAL histogram_valid        : STD_LOGIC;
 
-  SIGNAL sum_of_bins           : NATURAL;
-  SIGNAL verification_done     : STD_LOGIC;
+  SIGNAL sum_of_bins            : NATURAL;
+  SIGNAL verification_done      : STD_LOGIC;
 
 
 BEGIN 
@@ -188,13 +186,10 @@ BEGIN
       nxt_stimuli_src_out.valid <= '1';
       stimuli_count <= 0.0;
       FOR I IN 0 TO g_nof_sync-1 LOOP       
---        nxt_stimuli_src_out.data <= (OTHERS=>'0');
---        stimuli_data <= (OTHERS=>'0');
         nxt_stimuli_src_out.sync <= '1'; -- cycle 0
         WAIT FOR 5 ns;
         FOR j IN 1 TO g_nof_data_per_sync-1 LOOP --cycles 1..g_nof_data_per_sync-1
           nxt_stimuli_src_out.sync <= '0';
---          stimuli_data <= TO_SVEC( integer(round( c_sine_amplitude * sin(stimuli_count) )), g_data_w);
           nxt_stimuli_src_out.data(g_data_w-1 DOWNTO 0) <= TO_SVEC( integer(round( c_sine_amplitude * sin(stimuli_count) )), g_data_w);
           stimuli_count<=stimuli_count+c_sine_time_step;
           WAIT FOR 5 ns;
@@ -206,13 +201,13 @@ BEGIN
     IF g_stimuli_mode="random" THEN
       nxt_stimuli_src_out.valid <= '1';
       FOR I IN 0 TO g_nof_sync-1 LOOP
-        stimuli_data <= (OTHERS=>'0');
+        random_data <= (OTHERS=>'0');
         nxt_stimuli_src_out.sync <= '1'; -- cycle 0
         WAIT FOR 5 ns;
         FOR j IN 1 TO g_nof_data_per_sync-1 LOOP
           nxt_stimuli_src_out.sync <= '0';
-          stimuli_data <=  func_common_random(stimuli_data);
-          nxt_stimuli_src_out.data(g_data_w-1 DOWNTO 0) <= stimuli_data; --all g_nof_data_per_sync cycles
+          random_data <=  func_common_random(random_data);
+          nxt_stimuli_src_out.data(g_data_w-1 DOWNTO 0) <= random_data; --all g_nof_data_per_sync cycles
           WAIT FOR 5 ns;
         END LOOP;
       END LOOP;     
@@ -232,8 +227,10 @@ BEGIN
       stimuli_src_out <= nxt_stimuli_src_out;
     END IF;
   END PROCESS;
- 
---  nxt_stimuli_src_out.data(g_data_w-1 DOWNTO 0) <= stimuli_data;  
+
+  -- signal to verify histogram by eye in the wave window
+  stimuli_data <= stimuli_src_out.data(g_data_w-1 DOWNTO 0);
+
 
   ----------------------------------------------------------------------------
   -- st_histogram