一. 程式程式碼
1. 分頻模組

LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL; 
ENTITY fen_pin IS
PORT(          CLK : IN  STD_LOGIC;
             CLK_1 : OUT STD_LOGIC ); 
END fen_pin;

ARCHITECTURE BEHAV OF fen_pin IS 
  SIGNAL  A : INTEGER RANGE 0 TO 2499;
  SIGNAL  Q : STD_LOGIC;

  BEGIN
    PROCESS(CLK)   ----5000分頻得到1Hz的頻率（假設系統頻率為5KHz）
 

    BEGIN             
      IF CLK'EVENT AND CLK='1' THEN
        IF A=2499 THEN
              Q <= NOT Q;
              A <= 0;
        ELSE  A <= A+1;END IF;
      END IF;
    END PROCESS;

  CLK_1 <= Q;
 END;          

1. 控制模組

LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL; 
USE IEEE.STD_LOGIC_ARITH.ALL
 
;
USE IEEE.STD_LOGIC_UNSIGNED.ALL;
ENTITY kong_zhi IS
PORT(              CLK_1 : IN STD_LOGIC;
         EMERGENCY,RESET : IN STD_LOGIC;
               NUM1,NUM2 : OUT STD_LOGIC_VECTOR(3 DOWNTO 0);
                  LIGHT1 : OUT STD_LOGIC_VECTOR(2 DOWNTO 0);--A通道交通燈
                  LIGHT2 : OUT STD_LOGIC_VECTOR
 
(2 DOWNTO 0)); --B通道交通燈
END kong_zhi;

ARCHITECTURE BEHAV OF kong_zhi IS 
  TYPE   STATES IS (S0,S1,S2,S3,S4);---五個狀態。包括一個緊急狀態S0
  SIGNAL STATE : STATES;
  SIGNAL A,B,C,D : INTEGER RANGE 0 TO 9;
  SIGNAL EMERGENCY_STATE,RESET_STATE : STD_LOGIC := '0';
  SIGNAL COUNT : INTEGER RANGE 0 TO 49;

  BEGIN
    PROCESS(EMERGENCY)   ---緊急狀態
    BEGIN
      EMERGENCY_STATE <= EMERGENCY;
    END PROCESS;

    PROCESS(RESET)     ----復位
    BEGIN
      RESET_STATE <= RESET;
    END PROCESS;

    PROCESS(CLK_1)   
    BEGIN
      IF(RESET_STATE = '1')THEN  ----減計數。一次完整的狀態轉換需要50秒鐘
        COUNT <= 49;
      ELSE IF(EMERGENCY_STATE = '1')THEN
        COUNT <= COUNT;
      ELSE 
        IF(CLK_1'EVENT AND CLK_1='1')THEN
          IF COUNT = 0 THEN
            COUNT <= 49;
          ELSE COUNT <= COUNT-1;
          END IF;
        END IF;
      END IF;
      END IF;
    END PROCESS;

    PROCESS(EMERGENCY_STATE,COUNT)
    VARIABLE Q1,Q2 : INTEGER RANGE 0 TO 9;
    BEGIN
      IF(EMERGENCY_STATE = '1')THEN STATE <= S0;---各狀態持續的時間
      ELSE 
             IF(COUNT >= 30)THEN STATE <= S1;
        ELSE IF(COUNT >= 25 AND COUNT <= 29)THEN STATE <= S2;
        ELSE IF(COUNT >= 5 AND COUNT <= 24)THEN STATE <= S3;
        ELSE                                     STATE <= S4;
        END IF;
      END IF;
      END IF;
      END IF;
      CASE STATE IS
        WHEN S0 => LIGHT1 <= "010";---狀態S0，A  B通道都亮紅燈
                   LIGHT2 <= "010";
        WHEN S1 => LIGHT1 <= "100";---狀態S1，A通道亮綠燈  B通道亮紅燈
                   LIGHT2 <= "010";
        WHEN S2 => LIGHT1 <= "001";---狀態S2，A通道亮黃燈  B通道亮紅燈
                   LIGHT2 <= "010";
        WHEN S3 => LIGHT1 <= "010";---狀態S3，A通道亮紅燈  B通道亮綠燈
                   LIGHT2 <= "100";
        WHEN S4 => LIGHT1 <= "010";---狀態S4，A通道亮紅燈  B通道亮黃燈
                   LIGHT2 <= "001";
      END CASE;

      Q1 := COUNT/10;
      Q2 := COUNT REM 10;
      NUM1 <= CONV_STD_LOGIC_VECTOR(Q1, 4);---將COUNT計數器十位數轉換
----成二進位制數輸出
      NUM2 <= CONV_STD_LOGIC_VECTOR(Q2, 4); ---將COUNT計數器個位數轉換
----成二進位制數輸出
    END PROCESS;                              ----經七段譯碼器顯示在數碼管上

 END;

七段譯碼器程式碼省略