diff --git a/rtl/generator/src/generator.sv b/rtl/generator/src/generator.sv
index 89aab4a..118fed6 100644
--- a/rtl/generator/src/generator.sv
+++ b/rtl/generator/src/generator.sv
@@ -58,7 +58,7 @@ module generator
             end
             if (enable) begin
                 if (!sample_req && (cnt_period == 0)) begin
-                    pulse_height_out_reg <= '0;
+                    pulse_height_out_reg <= ZERO_LEVEL;
                     if (sample_done) begin
                         sample_req <= 1'b0;
                     end