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 == 0)begin
		c <= 9'd0;
	end
	else begin
		if( a > b)
			//c <= {a[7],a} - {b[7],b};
			c <= a - b;
		else
			//c <= {b[7],b} - {a[7],a};
			c <= b - a;
	end
end
endmodule