`timescale 1ns/1ns module calculation( input clk, input rst_n, input [3:0] a, input [3:0] b, output [8:0] c ); wire[7:0] a_temp, b_temp; reg[8:0] c_temp; mul mul1( .clk(clk), .rst_n(rst_n), .a(a), .b(4'd12), .c(a_temp) ); mul mul2( .clk(clk), .rst_n(rst_n), .a(b), .b(4'...