module timer(
    input   wire        sys_clk     ,
    input   wire        sys_rst_n   ,

    output  wire [4: 0] hour        ,
    output  wire [5: 0] min         ,
    output  wire [5: 0] sec
);
parameter MAX = 28'd50_000_000;
parameter DAY = 17'd86400;
reg [27: 0] cnt_s;//秒计数寄存器
reg [16: 0] cnt_day;//一天多少秒计数寄存器
//秒计数器设计
always @(posedge sys_clk or negedge sys_rst_n) begin
    if(!sys_rst_n)begin
        cnt_s <= 28'd0;
    end 
    else if(cnt_s == MAX - 1'd1)begin
        cnt_s <= 28'd0;
    end 
    else begin
        cnt_s <= cnt_s + 1'd1;
    end 
end
//天计数器设计
always @(posedge sys_clk or negedge sys_rst_n)begin
    if(!sys_rst_n)begin
        cnt_day <= 17'd0;
    end 
    else if((cnt_day == DAY - 1'd1) && (cnt_s == MAX - 1'd1))begin
        cnt_day <= 17'd0;
    end 
    else if(cnt_s == MAX - 1'd1)begin
        cnt_day <= cnt_day + 1'd1;
    end 
    else begin
        cnt_day <= cnt_day;
    end 
end 
assign hour = cnt_day / 3600;//解析小时
assign min  = cnt_day % 3600 / 60;//解析分钟
assign sec  = cnt_day % 60;//解析秒
endmodule