`timescale 1ns/1ns module calculation( input clk, input rst_n, input [3:0] a, input [3:0] b, output [8:0] c ); //c=12*a+5*b=8a+4a+4b+b reg [8:0] a1,b1,c1; // assign a1={5'b0,a}; // assign b1={5'b0,b}; // assign c= (a1<<3)+(a1<<2)+(b1<<2)+b; always@(posedge clk or negedge rst_n) if(...