jtdkz.vhd

这是本人在Max plus2环境下用VHDL语言编的交通灯控制程序。做EDA课程设计的朋友可以下来参考参考。

LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL;
ENTITY JTDKZ IS
PORT(CLK,SM,SB: IN STD_LOGIC;
     MR,MY,MG,BR,BY,BG: OUT STD_LOGIC);
END ENTITY JTDKZ;

ARCHITECTURE one OF JTDKZ IS
  TYPE STATE_TYPE IS (A,B,C,D);
  SIGNAL STATE: STATE_TYPE;

BEGIN 
CNT: PROCESS(CLK) IS
     VARIABLE S:INTEGER RANGE 0 TO 25;
     VARIABLE CLR,EN :BIT;
     
BEGIN
IF (CLK'EVENT AND CLK='1') THEN 
  IF CLR='0' THEN 
   S:=0;
  ELSIF EN='0' THEN 
   S:=S;
  ELSE 
   S:=S+1;
  END IF;

CASE STATE IS 
WHEN A=>MR<='0';MY<='0';MG<='1';
        BR<='1';BY<='0';BG<='0';
    IF(SB AND SM)='1' THEN 
        IF S=25 THEN 
          STATE<=B;CLR:='0';EN:='0';
         ELSE
         STATE<=A;CLR:='1';EN:='1';
        END IF;
     ELSIF (SB AND (NOT SM))='1' THEN
     STATE<=B;CLR:='0';EN:='0';
     ELSE 
     STATE<=A; CLR:='1';EN:='1';
   END IF;

WHEN B=>MR<='0';MY<='1';MG<='0';
        BR<='1';BY<='0';BG<='0';
      IF S=5 THEN 
        STATE<=C;CLR:='0';EN:='0';
      ELSE
       STATE<=B;CLR:='1';EN:='1';
     END IF;

WHEN C=>MR<='1';MY<='0';MG<='0';
        BR<='0';BY<='0';BG<='1';
    IF (SM AND SB)='1' THEN 
      IF S=15 THEN
       STATE<=D; CLR:='0';EN:='0';
      ELSE
        STATE<=C;CLR:='1';EN:='1';
      END IF;
    ELSIF SB='0'THEN
       STATE<=D;CLR:='0';EN:='0';
   ELSE 
      STATE<=C;CLR:='1';EN:='1';
  END IF;


WHEN D=>MR<='1';MY<='0';MG<='0';
        BR<='0';BY<='1';BG<='0';
    IF S=5 THEN 
   STATE<=A;CLR:='0';EN:='0';
   ELSE 
   STATE<=D;CLR:='1';EN:='1';
   END IF;
  END CASE;
END IF;
END PROCESS CNT;
END ARCHITECTURE one;