fdivyear.v

用verlog HDL写的电子日历,可以显示年,月,日和时间,具有闹铃的功能

//=====对年计数，并根据哪年是闰年产生leapyear信号=====//     
module fdivyear(clki,clr,year,leapyear);
  input clki,clr;
  output year,leapyear;
  reg[7:0] year;
  reg leapyear;  
  always @(posedge clki or posedge clr)
     begin
       if(clr)                           // 异步清零
          year=0;
       else                              // 计数
         begin
           if(year>=8'h99)              
             year=0;
           else if(year[3:0]>=9)        // 将二进制码变为BCD码
             year=year+7;
           else
             year=year+1;   
        // 列举出产生闰年的条件
          leapyear= (year==8'h4 || year==8'h8 || year==8'h12 || year==8'h16 ||
					 year==8'h20 || year==8'h24 || year==8'h28 || year==8'h32 ||
					 year==8'h36 || year==8'h40 || year==8'h44 || year==8'h48 ||
					 year==8'h52 || year==8'h56 || year==8'h60 || year==8'h64 ||
					 year==8'h68 || year==8'h72 || year==8'h76 || year==8'h80 ||
					 year==8'h84 || year==8'h88 || year==8'h92 || year==8'h96 );
         end
	end
endmodule
/* 闰年的判断法：
   最简单的方法是求模，但是Max+PlusII并不