`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] pro0,pro1; mult_4 u0 ( .clk (clk), .rst_n (rst_n), .data_a (4'd12), .data_b (a), .prod (pro0) ); mult_4 u1 ( .clk (clk), .rst_n (rst_n), .data_a (4'd5), .dat...