`timescale 1ns/1ns module calculation( input clk, input rst_n, input [3:0] a, input [3:0] b, output [8:0] c ); reg [8:0] c_r; reg [8:0] cr2; always @(posedge clk or negedge rst_n) begin if(!rst_n) begin c_r = 0; cr2 = 0; end else begin c_r <= a+a+a+a+a+a +a+a+a+a+a+a +b+b...