traffic.v

Verilog HDL语言设计的交通灯设计

/* 信号定义与说明: 
CLK: 为同步时钟; 
EN: 使能信号,为1的话,则控制器开始工作; 
LAMPA: 控制A方向四盏灯的亮灭;其中,LAMPA0~LAMPA3,分别控制A方向的 
左拐灯,绿灯,黄灯和红灯; 
LAMPB: 控制B方向四盏灯的亮灭;其中,LAMPB0 ~ LAMPB3,分别控制B方向的 
左拐灯,绿灯,黄灯和红灯; 
ACOUNT: 用于A方向灯的时间显示,8位,可驱动两个数码管; 
BCOUNT: 用于B方向灯的时间显示,8位,可驱动两个数码管. */ 

module traffic(CLK,EN,LAMPA,LAMPB,ACOUNT,BCOUNT); 
output[7:0] ACOUNT,BCOUNT; 
output[3:0] LAMPA,LAMPB; 
input CLK,EN; 
reg[7:0] numa,numb; 
reg tempa,tempb; 
reg[2:0] counta,countb; 
reg[7:0] ared,ayellow,agreen,aleft,bred,byellow,bgreen,bleft; 
reg[3:0] LAMPA,LAMPB; 
    always @(EN) 
       if(!EN) 
          begin //设置各种灯的计数器的预置数 
            ared <=8'd55; //55秒 
            ayellow <=8'd5; //5秒 
            agreen <=8'd40; //40秒 
            aleft <=8'd15; //15秒 
            bred <=8'd65; //65秒 
            byellow <=8'd5; //5秒 
            bleft <=8'd15; //15秒 
            bgreen <=8'd30; //30秒 
          end 

    assign ACOUNT=numa; 
    assign BCOUNT=numb; 
    always @(posedge CLK) //该进程控制A方向的四种灯 
        begin 
          if(EN) 
            begin 
              if(!tempa) 
                begin 
                 tempa<=1; 
                  case(counta) //控制亮灯的顺序 
                      0: begin numa<=agreen; LAMPA<=2; counta<=1; end 
                      1: begin numa<=ayellow; LAMPA<=4; counta<=2; end 
                      2: begin numa<=aleft; LAMPA<=1; counta<=3; end 
                      3: begin numa<=ayellow; LAMPA<=4; counta<=4; end 
                      4: begin numa<=ared; LAMPA<=8; counta<=0; end 
                      default: LAMPA<=8;
                  endcase
                 end
               else 
                begin
                  if(numa>1) 
                   if(numa[3:0]==0) 
                     begin 
                       numa[3:0]<=4'b1001; 
                       numa[7:4]<=numa[7:4]-1; 
                     end 
                    else numa[3:0]<=numa[3:0]-1; 
                     if (numa==2) 
                       tempa<=0; 
                     end 
                    end 
                   else 
                    begin 
                     LAMPA<=4'b1000; 
                     counta<=0; tempa<=0; 
                    end 
                   end
     always @(posedge CLK) //该进程控制B方向的四种灯 
            begin 
             if (EN) 
                begin 
                 if(!tempb) 
                   begin 
                      tempb<=1; 
                   case (countb) //控制亮灯的顺序 
                       0: begin numb<=bred; LAMPB<=8; countb<=1; end 
                       1: begin numb<=bgreen; LAMPB<=2; countb<=2; end 
                       2: begin numb<=byellow; LAMPB<=4; countb<=3; end 
                       3: begin numb<=bleft; LAMPB<=1; countb<=4; end 
                       4: begin numb<=byellow; LAMPB<=4; countb<=0; end 
                       default:      LAMPB<=8;
                    endcase
                    end
                  else 
                   begin
                    if(numb>1)
                     if(!numb[3:0]) 
                      begin 
                       numb[3:0]<=9; 
                       numb[7:4]<=numb[7:4]-1; 
                      end 
                     else
                       numb[3:0]<=numb[3:0]-1; 
                       if(numb==2) 
                         tempb<=0; 
                       end 
                      end 
                     else 
                       begin 
                        LAMPB<=4'b1000; 
                        tempb<=0; countb<=0; 
                       end 
                     end 
endmodule