關於FIFO異步復位的問題

關於FIFO異步復位的問題

FIFO異步復位的寬度，需要保證至少3個較慢時鍾的時鍾周期長度。

怎樣對一個脈沖加寬呢？

`timescale 1ns / 1ps
//////////////////////////////////////////////////////////////////////////////////
// Company: 
// Engineer: 
// 
// Create Date: 2018/08/08 19:03:20
// Design Name: 
// Module Name: signal_wide
// Project Name: 
// Target Devices: 
// Tool Versions: 
// Description: 
// 
// Dependencies: 
// 
// Revision:
// Revision 0.01 - File Created
// Additional Comments:
// 
//////////////////////////////////////////////////////////////////////////////////


module signal_wide(

    input  wire  clk,
    input  wire  rst,
    input  wire  signal
    );



reg [7:0] signal_delay = 0;
reg       signal_delay_wide = 0;
always @ (posedge clk or posedge rst)
begin
    if(rst)
    begin
        signal_delay <= 8'b0;
        signal_delay_wide <= 1'b0;
    end

    else 
    begin
        signal_delay <= {signal_delay[6:0],signal};
        signal_delay_wide <= | signal_delay;
    end
end


endmodule


/*

add_force {/signal_wide/clk} -radix hex {1 0ns} {0 50000ps} -repeat_every 100000ps
add_force {/signal_wide/rst} -radix hex {1 0ns} {0 200ns}
add_force {/signal_wide/signal} -radix hex {0 0ns} {1 600ns} {0 700ns}




*/