diff --git a/rtl/generator/tests/generator_tb.sv b/rtl/generator/tests/generator_tb.sv
index 621766a..4ef2322 100644
--- a/rtl/generator/tests/generator_tb.sv
+++ b/rtl/generator/tests/generator_tb.sv
@@ -229,7 +229,8 @@ module generator_tb;
         input int pulse_p,
         input int pulse_n,
         input int pulse_h,
-        input bit skip_reset
+        input bit skip_reset,   // skip reset sequence on demand
+        input bit count_level   // count ticks of amplitude == pulse_h or amplitude != pulse_h
     );
         int total_impulse_cycles = 0;
 
@@ -253,8 +254,15 @@ module generator_tb;
             begin : counter_proc
                 forever begin
                     @(posedge dac_wrt);
-                    if (dac_out == pulse_h) begin
-                        total_impulse_cycles++;
+                    if (count_level) begin
+                        if (dac_out == pulse_h) begin
+                            total_impulse_cycles++;
+                        end
+                    end
+                    else begin
+                        if (dac_out != current_zero_level) begin
+                            total_impulse_cycles++;
+                        end
                     end
                 end
             end
@@ -271,11 +279,21 @@ module generator_tb;
         disable counter_proc;
         repeat(10) @(posedge clk);
 
-        if (total_impulse_cycles == pulse_w*pulse_n)
-            $display("[TB] -run_test_case- Pulse generation CORRECT");
+        if (count_level) begin
+            if (total_impulse_cycles == pulse_w*pulse_n)
+                $display("[TB] -run_test_case- Pulse generation CORRECT");
+            else begin
+                    $display("[ERROR] -run_test_case- Pulse generation INCORRECT. Total number of pulses: %d, must be: %d", total_impulse_cycles, pulse_w*pulse_n);
+                    $finish;
+            end
+        end
         else begin
-                $display("[ERROR] -run_test_case- Pulse generation INCORRECT. Total number of pulses: %d, must be: %d", total_impulse_cycles, pulse_w*pulse_n);
-                $finish;
+            if (total_impulse_cycles == 0)
+                $display("[TB] -run_test_case- Pulse generation CORRECT");
+            else begin
+                    $display("[ERROR] -run_test_case- Pulse generation INCORRECT. Total number of pulses: %d, must be: %d", total_impulse_cycles, 0);
+                    $finish;
+            end
         end
     endtask
 
@@ -321,11 +339,23 @@ module generator_tb;
                 .pulse_p(r_p), 
                 .pulse_n(r_n), 
                 .pulse_h(r_h), 
-                .skip_reset(r_skip)
+                .skip_reset(r_skip),
+                .count_level(1)
             );
         end
         $display("[TB] Test 2 complete");
 
+        $display("[TB] Test 3. Zero level of pulse height");
+        run_test_case(
+            .pulse_w(77), 
+            .pulse_p(131), 
+            .pulse_n(13), 
+            .pulse_h(current_zero_level), 
+            .skip_reset(0),
+            .count_level(0)
+        );
+        $display("[TB] Test 3 complete");
+
         $display("[TB] All Tests complete!");
         $finish;
     end