题解 | #任意奇数倍时钟分频#

`timescale 1ns/1ns

module clk_divider
    #(parameter dividor = 5)
(     input clk_in,
    input rst_n,
    output clk_out
);
    parameter qq = dividor ;
    reg [qq-1:0] cnt;
    always @(posedge clk_in or negedge rst_n) begin
        if(!rst_n)
            cnt <= 'd0;
        else if(cnt==qq-1)
            cnt <= 'd0;
        else
            cnt <= cnt + 1'b1;
    end
    reg clk1,clk2;
    always @(posedge clk_in or negedge rst_n) begin
        if(!rst_n)
            clk1<=1'b1;
        else if(cnt==qq-1)
            clk1<=~clk1;
        else
            clk1 <= clk1;
    end
    always @(negedge clk_in or negedge rst_n) begin
        if(!rst_n)
            clk2<=1'b1;
        else if(cnt==(qq-1)/2)
            clk2<=~clk2;
        else
            clk2 <= clk2;
    end
    assign clk_out = clk1 ^ clk2;
endmodule