专栏前言
本专栏的内容主要是记录本人学习Verilog过程中的一些知识点,刷题网站用的是牛客网
`timescale 1ns/1nsmodule div_M_N(input wire clk_in,input wire rst,output wire clk_out
);parameter M_N = 8'd87; parameter c89 = 8'd24; // 8/9时钟切换点parameter div_e = 5'd8; //偶数周期parameter div_o = 5'd9; //奇数周期
//*************code***********//reg [3:0] clk_cnt ; reg [6:0] cyc_cnt ;reg div_flag ; reg clk_out_r ; always @ (posedge clk_in or negedge rst) begin if (~rst) clk_cnt <= 0 ; else if (~div_flag) clk_cnt <= clk_cnt == (div_e - 1) ? 0 : clk_cnt + 1 ; else clk_cnt <= clk_cnt == (div_o - 1) ? 0 : clk_cnt + 1 ; endalways @ (posedge clk_in or negedge rst) begin if (~rst) cyc_cnt <= 0 ; else cyc_cnt <= cyc_cnt == (M_N - 1) ? 0 : cyc_cnt + 1 ; endalways @ (posedge clk_in or negedge rst) beginif (~rst) div_flag <= 0 ; else div_flag <= cyc_cnt == (M_N - 1) || cyc_cnt == (c89 - 1) ? ~div_flag : div_flag ; endalways @ (posedge clk_in or negedge rst) begin if (~rst) clk_out_r <= 0 ; else if (~div_flag) clk_out_r <= clk_cnt <= ((div_e >> 2) + 1) ; // cnt == 0,1,2,3 out输出1else clk_out_r <= clk_cnt <= ((div_o >> 2) + 1) ;endassign clk_out = clk_out_r ; //*************code***********//
endmodule
参考资料:题解 | #任意小数分频#_牛客博客