题解 | 求两个数的差值

`timescale 1ns/1ns
module data_minus(
	input clk,
	input rst_n,
	input [7:0]a,
	input [7:0]b,

	output  reg [8:0]c
);

    always @(posedge clk or negedge rst_n) begin
        if (~rst_n) begin
            c <= 0;
        end else if (a>b) begin
            c <= a - b;            
        end else if (a<=b) begin
            c <= b - a;            
        end
    end
endmodule