[FPGA] Timer Verilog Code

카운트다운 모듈 동작 목표

1) 1번버튼을 누르면 초단위 UP

2) 2번버튼 누르면 min단위 UP

3) 3번버튼 누르면 Reset 초기화

4) 4번 버튼 누르면 Count Down 시작

+ 카운트 다운중에 0이 되면 자동으로 동작 멈추고 0으로 고정되며 불이켜짐

 

Dflipflop : 버튼의 채터링 방지 

Tflipflop : T가 1일때, Clk에 어떤 값을 입력하면, 버튼 처럼 Toggle 되는 Output을 낼때 + 리셋값이 들어오면 출력값을  안내도록 할때

 

아래 코드를 보면 T1까지 기본 타이머 구현이고,

그 이후는 0값이 되면 카운트 다운이 자동으로 멈춰 0으로 초기화 하고, LED가 켜짐을 나타내는 코드

 

 

module cook_timer_module(

    input clk,
    input [3:0] btn,
    output [3:0] led,
    output [3:0] com,
    output [6:0] seg_7
    );
    
    wire [3:0] sec_1, sec_10, min_1, min_10;
    wire countdown_enable;
    wire [3:0] debounced_btn;
    wire clk_usec, clk_msec, clk_sec_1;
    wire [3:0] hex_value;
    wire countdown_enable_bar, clk_sec_1_bar, sec_up_clk;
    wire sec_down_clk, sec_up_down_clk, dec_clk;
    wire min_up_clk, min_down_clk, min_up_down_clk;
    wire led_off;
    wire btn3_bar;
    wire time_out, end_of_count, toggle_enable;
        
    D_flip_flop DFF0 (.D(btn[0]), .clk(clk_msec), .reset(1'b1), 
        .preset(1'b1), .Q(debounced_btn[0]));
    D_flip_flop DFF1 (.D(btn[1]), .clk(clk_msec), .reset(1'b1), 
        .preset(1'b1), .Q(debounced_btn[1]));
    D_flip_flop DFF2 (.D(btn[2]), .clk(clk_msec), .reset(1'b1), 
        .preset(1'b1), .Q(debounced_btn[2]));
    D_flip_flop DFF3 (.D(btn[3]), .clk(clk_msec), .reset(1'b1), 
        .preset(1'b1), .Q(debounced_btn[3]));
    clock_usec G_usec (.clk(clk), .clk_usec(clk_usec));
    clock_msec G_msec (.clk_usec(clk_usec), .clk_msec(clk_msec));
    clock_sec_1 G_sec_1 (.clk_msec(clk_msec), .clk_sec_1(clk_sec_1));
    FND4digit_switcher S (
        .value_1(sec_1),
        .value_10(sec_10),
        .value_100(min_1),
        .value_1000(min_10),
        .clk_msec(clk_msec),
        .hex_value(hex_value),
        .com(com));
    decoder_7_seg D7 (.hex_value(hex_value), .seg_7(seg_7));
    
    not (countdown_enable_bar, countdown_enable);
    not (clk_sec_1_bar, clk_sec_1);
    and (sec_up_clk, debounced_btn[0], countdown_enable_bar);
    and (sec_down_clk, clk_sec_1_bar, countdown_enable);
    or (sec_up_down_clk, sec_up_clk, sec_down_clk);
    counter_up_down counter_sec (
        .up_down(countdown_enable),
        .up_down_clk(sec_up_down_clk),
        .reset(debounced_btn[3]),
        .count_1(sec_1),
        .count_10(sec_10),
        .dec_clk(dec_clk)
    );
    
    and (min_up_clk, debounced_btn[1], countdown_enable_bar);
    and (min_down_clk, dec_clk, countdown_enable);
    or (min_up_down_clk, min_up_clk, min_down_clk);
    counter_up_down counter_min (
        .up_down(countdown_enable),
        .up_down_clk(min_up_down_clk),
        .reset(debounced_btn[3]),
        .count_1(min_1),
        .count_10(min_10)
    );
    
    not(btn3_bar, debounced_btn[3]);   
    
    T_flip_flop T1 (
        .T(1'b1),
        .clk(toggle_enable),
        .reset(btn3_bar),
        .Q(countdown_enable)
    );
    
    nor (time_out, 
            sec_1[0], sec_1[1], sec_1[2], sec_1[3],
            sec_10[0], sec_10[1], sec_10[2], sec_10[3],
            min_1[0], min_1[1], min_1[2], min_1[3],
            min_10[0], min_10[1], min_10[2], min_10[3]);
    and (end_of_count, countdown_enable, time_out);
    or (toggle_enable, debounced_btn[2], end_of_count);
    
    nor (led_off, 
        debounced_btn[0], debounced_btn[1], debounced_btn[2], debounced_btn[3]);
    T_flip_flop T2 (
        .T(1'b1),
        .clk(time_out),
        .reset(led_off),
        .Q(led[0])
    );
    
endmodule