题解 | #脉冲同步器（快到慢）#

`timescale 100ps/100ps

module pulse_detect(
	input 				clka	, 
	input 				clkb	,   
	input 				rst_n		,
	input				sig_a		,

	output  		 	sig_b
);
wire sig_b;
//脉冲电平检测，双极性触发，边沿检测
reg q ,q_reg1 ,q_reg2,q_reg3;

always @(posedge clka or negedge rst_n) 
	if(!rst_n) 
		q<= 0;
	else if(sig_a)
		q<= !q;
	
always @(posedge clkb or negedge rst_n) 
	if(!rst_n) begin
		q_reg1 <= 0;
		q_reg2 <= 0;
	end
	else begin 
		q_reg1<= q;
		q_reg2 <= q_reg1;
	end

always @(posedge clkb or negedge rst_n) 
	if(!rst_n) 
		q_reg3<=0;
	else
		q_reg3<=q_reg2;

	assign sig_b = q_reg2^q_reg3;
endmodule