3215_Lab5

module Lab5(
                input CLOCK_50,
                input [3:0] KEY,
                output reg [1:0] LEDR,
                inout [35:0] GPIO_0,
                output reg [6:0] HEX0, HEX1, HEX2, HEX3, HEX4, HEX5, HEX6, HEX7
);

     reg [31:0] time4k, time50, count;
     reg flag;
     wire [6:0] h0,h1,h2,h3,h4,h5,h6,h7;

    hex_7seg(count%10, h0);
     hex_7seg(count/10%10, h1);
     hex_7seg(count/100%10, h2);
     hex_7seg(count/1000%10, h3);

    initial begin
        time50 = 0;
          time4k = 0;
    end
    always @(posedge CLOCK_50) begin
        if(time50 >= 12500) begin
            time4k = time4k + 1;
            if(time4k >=4000) begin
                    LEDR[0] = 1'b1;
                    flag = 1;
            end
            else begin
                LEDR[0] = 1'b0;
                flag = 0;
            end
            time50 = 0;
        end

        time50 = time50+1;
        HEX0 <= h0;
        HEX1 <= h1;
        HEX2 <= h2;
    end

     always@(negedge GPIO_0[0] && !flag) begin
        count <= count + 1;
     end

endmodule


module hex_7seg(hex_digit,seg);
input [3:0] hex_digit;
output [6:0] seg;
reg [6:0] seg;
// seg = {g,f,e,d,c,b,a};
// 0 is on and 1 is off

always @ (hex_digit)
case (hex_digit)
        4'h0: seg = 7'b1000000;
        4'h1: seg = 7'b1111001;     // ---a----
        4'h2: seg = 7'b0100100;     // |      |
        4'h3: seg = 7'b0110000;     // f      b
        4'h4: seg = 7'b0011001;     // |      |
        4'h5: seg = 7'b0010010;     // ---g----
        4'h6: seg = 7'b0000010;     // |      |
        4'h7: seg = 7'b1111000;     // e      c
        4'h8: seg = 7'b0000000;     // |      |
        4'h9: seg = 7'b0011000;     // ---d----
        4'ha: seg = 7'b0001000;
        4'hb: seg = 7'b0000011;
        4'hc: seg = 7'b1000110;
        4'hd: seg = 7'b0100001;
        4'he: seg = 7'b0000110;
        4'hf: seg = 7'b0001110;
endcase
endmodule