【时钟分频】— 50MHz产生12.5MHz的4分频时钟

一、设计文件

module div_clk(
    input    wire    sclk,
    input    wire    rst_n,
    output    wire    po_div_clk
);
 
parameter    DIV_END = 8'd3;
reg        [7:0]    div_cnt;
reg                div_clk_o;
    
//div_cnt
always @ (posedge sclk or negedge rst_n)
    if(rst_n == 1'b0)
        div_cnt <= 'd0;
    else if(div_cnt == DIV_END)
        div_cnt <= 'd0;
    else 
        div_cnt <= div_cnt + 1'b1;
        
always @ (posedge sclk or negedge rst_n)
    if(rst_n == 1'b0)
        div_clk_o <= 1'b0;
    else if(div_cnt == 'd1)
        div_clk_o <= 1'b1;
    else if(div_cnt == 'd3)
        div_clk_o <= 1'b0;
 
assign po_div_clk = div_clk_o;
 
endmodule

二、测试文件

`timescale 1ns/1ns
 
module tb_div_clk;
 
reg     sclk,rst_n;
wire    po_div_clk;
 
initial begin
    sclk = 0;
    rst_n = 0;
    #100
    rst_n <= 1;
end
 
always # 10 sclk = ~sclk;
 
div_clk div_clk_inst(
        .sclk                (sclk),
        .rst_n                (rst_n),
        .po_div_clk            (po_div_clk)
);
 
endmodule

三、波形图