diff --git a/libraries/dsp/st/tb/vhdl/tb_tb_st_histogram.vhd b/libraries/dsp/st/tb/vhdl/tb_tb_st_histogram.vhd
index a69031c62ff166f1ee7344ded164c48bfae06eb9..3e3e103c21aa40006c08ff6095810b8496dfc7a4 100644
--- a/libraries/dsp/st/tb/vhdl/tb_tb_st_histogram.vhd
+++ b/libraries/dsp/st/tb/vhdl/tb_tb_st_histogram.vhd
@@ -25,7 +25,9 @@
 -- Usage
 -- . as 8
 -- . run -all 
--- . Testbenches are self-checking for g_stimuli_mode="counter" and "dc".
+-- . Testbenches are self-checking.
+-- . The sine wave test benches are best for verification by eye in the wave window.
+--   . tb_st_histogram uses a sine wave as input by default
 
 LIBRARY IEEE;
 USE IEEE.std_logic_1164.ALL;
@@ -45,18 +47,18 @@ BEGIN
 --  g_data_type    : STRING  := "unsigned"
 
 -- Counter data
-u_tb_st_histogram_0 : ENTITY work.tb_st_histogram GENERIC MAP ( 7,  8,  256, 1024, "counter", "unsigned"); -- Incoming data wraps (repeats) 1024/ 256= 4 times: Bin count =  4
-u_tb_st_histogram_1 : ENTITY work.tb_st_histogram GENERIC MAP ( 6, 10,  256, 4096, "counter", "unsigned"); -- Incoming data wraps (repeats) 4096/ 256=16 times: Bin count = 16
-u_tb_st_histogram_2 : ENTITY work.tb_st_histogram GENERIC MAP ( 5, 12,  512, 4096, "counter", "unsigned"); -- Incoming data wraps (repeats) 4096/ 512= 8 times: Bin count =  8
-u_tb_st_histogram_3 : ENTITY work.tb_st_histogram GENERIC MAP ( 4, 13, 1024, 8192, "counter", "unsigned"); -- Incoming data wraps (repeats) 8192/1024= 8 times: Bin count =  8
-u_tb_st_histogram_4 : ENTITY work.tb_st_histogram GENERIC MAP (20,  6,   64,  128, "counter", "unsigned"); -- Incoming data wraps (repeats)  128/  64= 2 times: Bin count =  2
+u_tb_st_histogram_0 : ENTITY work.tb_st_histogram GENERIC MAP ( 7,  8,  256, 1024, "counter", "unsigned"); -- Incoming data repeats 1024/ 256= 4 times: Bin count =  4
+u_tb_st_histogram_1 : ENTITY work.tb_st_histogram GENERIC MAP ( 6, 10,  256, 4096, "counter", "unsigned"); -- Incoming data repeats 4096/ 256=16 times: Bin count = 16
+u_tb_st_histogram_2 : ENTITY work.tb_st_histogram GENERIC MAP ( 5, 12,  512, 4096, "counter", "unsigned"); -- Incoming data repeats 4096/ 512= 8 times: Bin count =  8
+u_tb_st_histogram_3 : ENTITY work.tb_st_histogram GENERIC MAP ( 4, 13, 1024, 8192, "counter", "unsigned"); -- Incoming data repeats 8192/1024= 8 times: Bin count =  8
+u_tb_st_histogram_4 : ENTITY work.tb_st_histogram GENERIC MAP (20,  6,   64,  128, "counter", "unsigned"); -- Incoming data repeats  128/  64= 2 times: Bin count =  2
 
 -- DC signal
-u_tb_st_histogram_5 : ENTITY work.tb_st_histogram GENERIC MAP ( 2,  8,  256, 1024, "dc", "unsigned");
-u_tb_st_histogram_6 : ENTITY work.tb_st_histogram GENERIC MAP ( 6, 10,  256, 4096, "dc", "unsigned");
-u_tb_st_histogram_7 : ENTITY work.tb_st_histogram GENERIC MAP ( 5, 12,  512, 4096, "dc", "unsigned");
-u_tb_st_histogram_8 : ENTITY work.tb_st_histogram GENERIC MAP ( 4, 13, 1024, 8192, "dc", "unsigned");
-u_tb_st_histogram_9 : ENTITY work.tb_st_histogram GENERIC MAP (11,  6,   64,  128, "dc", "unsigned");
+u_tb_st_histogram_5 : ENTITY work.tb_st_histogram GENERIC MAP ( 2,  8,  256, 1000, "dc", "unsigned");
+u_tb_st_histogram_6 : ENTITY work.tb_st_histogram GENERIC MAP ( 6, 10,  256, 4000, "dc", "unsigned");
+u_tb_st_histogram_7 : ENTITY work.tb_st_histogram GENERIC MAP ( 5, 12,  512, 4000, "dc", "unsigned");
+u_tb_st_histogram_8 : ENTITY work.tb_st_histogram GENERIC MAP ( 4, 13, 1024, 8000, "dc", "unsigned");
+u_tb_st_histogram_9 : ENTITY work.tb_st_histogram GENERIC MAP (11,  6,   64,  100, "dc", "unsigned");
 
 -- Sine wave
 u_tb_st_histogram_10: ENTITY work.tb_st_histogram GENERIC MAP ( 4,  3,    8,   20, "sine", "signed");