diff --git a/chip_design_working_variable.sv b/chip_design_working_variable.sv
index 63b5938..55d454d 100644
--- a/chip_design_working_variable.sv
+++ b/chip_design_working_variable.sv
@@ -392,6 +392,7 @@ module stack_ncell #(
         if (rst_stack) begin
             stack_ptr <= 0;
             stack_sol_ptr <= 0;
+            mem <= '{default:2'b00};
         end else if (stack_sol_inc) begin
             stack_sol_ptr <= stack_sol_ptr + 1;
         end else if (stack_en) begin