hzxs.vhd

以FPGA芯片为核心

LIBRARY IEEE;
USE IEEE.STD_LOGIC_1164.ALL;
USE IEEE.STD_LOGIC_UNSIGNED.ALL;

ENTITY HZXS IS
  PORT(CLK,CLK1:IN STD_LOGIC;
       SEL:OUT STD_LOGIC_VECTOR(3 DOWNTO 0);
       L:OUT STD_LOGIC_VECTOR(15 DOWNTO 0));
END HZXS;

ARCHITECTURE A OF HZXS IS

  SIGNAL LIE:STD_LOGIC_VECTOR(3 DOWNTO 0);
  SIGNAL NEXT1:STD_LOGIC_VECTOR(1 DOWNTO 0);
BEGIN

PROCESS(CLK)IS
   BEGIN    
   IF CLK'EVENT AND CLK='1'THEN
      IF NEXT1="11"THEN
         NEXT1<="00";
      ELSE 
         NEXT1<=NEXT1+'1';
      END IF;
   END IF;
END PROCESS;

PROCESS(NEXT1,LIE)IS
      BEGIN
      CASE NEXT1 IS
      WHEN "00"=>
        CASE LIE IS
        WHEN"0011"=>L<="0000000000000000";
        WHEN"0100"=>L<="0000100000000000";
        WHEN"0101"=>L<="0000010000000000";
        WHEN"0110"=>L<="0000001000000000";
        WHEN"0111"=>L<="0000000100000000";
        WHEN"1000"=>L<="0011111111111110";              ----------显示’七’字
        WHEN"1001"=>L<="0010000001000000";
        WHEN"1010"=>L<="0010000000100000";
        WHEN"1011"=>L<="0010000000010000";
        WHEN"1100"=>L<="0010000000001000";
        WHEN"1101"=>L<="0011100000000000";
        WHEN"1110"=>L<="0000000000000000";
        WHEN OTHERS=>L<="0000000000000000";
        END CASE;
      WHEN "01"=>
        CASE LIE IS
        WHEN"0011"=>L<="0000000000000000";
        WHEN"0100"=>L<="0010000000000000";
        WHEN"0101"=>L<="0010000000000000";
        WHEN"0110"=>L<="0010000000000000";
        WHEN"0111"=>L<="0010000000000000";
        WHEN"1000"=>L<="0010000000000000";             -----------显示’上’字
        WHEN"1001"=>L<="0011111111111000";
        WHEN"1010"=>L<="0010000100000000";
        WHEN"1011"=>L<="0010000100000000";
        WHEN"1100"=>L<="0010000000000000";
        WHEN"1101"=>L<="0010000000000000";
        WHEN"1110"=>L<="0000000000000000";
        WHEN OTHERS=>L<="0000000000000000";
        END CASE;
      WHEN "10"=>
        CASE LIE IS
        WHEN"0011"=>L<="0000000000000000";
        WHEN"0100"=>L<="0000000100000000";
        WHEN"0101"=>L<="0000000010000000";
        WHEN"0110"=>L<="0000000001000000";
        WHEN"0111"=>L<="0000000000100000";
        WHEN"1000"=>L<="0000000000000100";
        WHEN"1001"=>L<="0000000000001000";              -----------显示’八’字
        WHEN"1010"=>L<="0000000000010000";
        WHEN"1011"=>L<="0000000000100000";
        WHEN"1100"=>L<="0000000001000000";
        WHEN"1101"=>L<="0000000010000000";
        WHEN"1110"=>L<="0000000100000000";
        WHEN OTHERS=>L<="0000000000000000";
        END CASE;
      WHEN "11"=>
        CASE LIE IS
        WHEN"0011"=>L<="0000000000000000";
        WHEN"0100"=>L<="0000000000000000";
        WHEN"0101"=>L<="0000000000001000";
        WHEN"0110"=>L<="0000000000001000";
        WHEN"0111"=>L<="0000000000001000";
        WHEN"1000"=>L<="0000000000001000";           ------------显示”下”字
        WHEN"1001"=>L<="0011111111111000";
        WHEN"1010"=>L<="0000000100001000";
        WHEN"1011"=>L<="0000000100001000";
        WHEN"1100"=>L<="0000000000001000";
        WHEN"1101"=>L<="0000000000001000";
        WHEN"1110"=>L<="0000000000000000";
        WHEN OTHERS=>L<="0000000000000000";
        END CASE;
     WHEN OTHERS=>L<="0000000000000000";
     END CASE;   
END PROCESS;

PROCESS(CLK1)IS
  BEGIN
  IF CLK1'EVENT AND CLK1='1'THEN
      IF LIE="1111"THEN
         LIE<="0000";
      ELSE 
         LIE<=LIE+'1';
      END IF;
  END IF;
END PROCESS;
SEL<=LIE;
END A;