xianshi.vhd

实现由一个4位十进制数码管（含小数点）显示结果

                         WHEN "10000001" => D0<="10000110";
                         WHEN "10000010" => D0<="11011011";
                         WHEN "10000011" => D0<="11001111";
                         WHEN "10000100" => D0<="11100110";
                         WHEN "10000101" => D0<="11101101";
                         WHEN "10000110" => D0<="11111100"; 
                         WHEN "10000111" => D0<="10000111";
                         WHEN "10001000" => D0<="11111111";
                         WHEN "10001001" => D0<="11100111";
                         WHEN OTHERS     => NULL;
                         END CASE;
                        CASE G1 IS
                         WHEN "00000000" => D1<="00111111";
                         WHEN "00000001" => D1<="00000110";
                         WHEN "00000010" => D1<="01011011";
                         WHEN "00000011" => D1<="01001111";
                         WHEN "00000100" => D1<="01100110";
                         WHEN "00000101" => D1<="01101101";
                         WHEN "00000110" => D1<="01111100";
                         WHEN "00000111" => D1<="00000111";
                         WHEN "00001000" => D1<="01111111";
                         WHEN "00001001" => D1<="01100111";
                         WHEN "10000000" => D1<="10111111";
                         WHEN "10000001" => D1<="10000110";
                         WHEN "10000010" => D1<="11011011";
                         WHEN "10000011" => D1<="11001111";
                         WHEN "10000100" => D1<="11100110";
                         WHEN "10000101" => D1<="11101101";
                         WHEN "10000110" => D1<="11111100"; 
                         WHEN "10000111" => D1<="10000111";
                         WHEN "10001000" => D1<="11111111";
                         WHEN "10001001" => D1<="11100111";
                         WHEN OTHERS     => NULL;
                         END CASE;
                       CASE G2 IS
                         WHEN "00000000" => D2<="00111111";
                         WHEN "00000001" => D2<="00000110";
                         WHEN "00000010" => D2<="01011011";
                         WHEN "00000011" => D2<="01001111";
                         WHEN "00000100" => D2<="01100110";
                         WHEN "00000101" => D2<="01101101";
                         WHEN "00000110" => D2<="01111100";
                         WHEN "00000111" => D2<="00000111";
                         WHEN "00001000" => D2<="01111111";
                         WHEN "00001001" => D2<="01100111";
                         WHEN "10000000" => D2<="10111111";
                         WHEN "10000001" => D2<="10000110";
                         WHEN "10000010" => D2<="11011011";
                         WHEN "10000011" => D2<="11001111";
                         WHEN "10000100" => D2<="11100110";
                         WHEN "10000101" => D2<="11101101";
                         WHEN "10000110" => D2<="11111100"; 
                         WHEN "10000111" => D2<="10000111";
                         WHEN "10001000" => D2<="11111111";
                         WHEN "10001001" => D2<="11100111";
                         WHEN OTHERS     => NULL;
                       END CASE;
                       D3<="00000000";   
                      end if;
              else
                  G0<=B0;G1<=B1;G2<=B2; G3<=B3;
                      CASE G0 IS
                         WHEN "00000000" => D0<="00111111";
                         WHEN "00000001" => D0<="00000110";
                         WHEN "00000010" => D0<="01011011";
                         WHEN "00000011" => D0<="01001111";
                         WHEN "00000100" => D0<="01100110";
                         WHEN "00000101" => D0<="01101101";
                         WHEN "00000110" => D0<="01111100";
                         WHEN "00000111" => D0<="00000111";
                         WHEN "00001000" => D0<="01111111";
                         WHEN "00001001" => D0<="01100111";
                         WHEN "10000000" => D0<="10111111";
                         WHEN "10000001" => D0<="10000110";
                         WHEN "10000010" => D0<="11011011";
                         WHEN "10000011" => D0<="11001111";
                         WHEN "10000100" => D0<="11100110";
                         WHEN "10000101" => D0<="11101101";
                         WHEN "10000110" => D0<="11111100"; 
                         WHEN "10000111" => D0<="10000111";
                         WHEN "10001000" => D0<="11111111";
                         WHEN "10001001" => D0<="11100111";
                         WHEN OTHERS     => NULL;
                         END CASE;
                  CASE G1 IS
                    WHEN "00000000" => D1<="00111111";
                    WHEN "00000001" => D1<="00000110";
                    WHEN "00000010" => D1<="01011011";
                    WHEN "00000011" => D1<="01001111";
                    WHEN "00000100" => D1<="01100110";
                    WHEN "00000101" => D1<="01101101";
                    WHEN "00000110" => D1<="01111100";
                    WHEN "00000111" => D1<="00000111";
                    WHEN "00001000" => D1<="01111111";
                    WHEN "00001001" => D1<="01100111";
                    WHEN "10000000" => D1<="10111111";
                    WHEN "10000001" => D1<="10000110";
                    WHEN "10000010" => D1<="11011011";
                    WHEN "10000011" => D1<="11001111";
                    WHEN "10000100" => D1<="11100110";
                    WHEN "10000101" => D1<="11101101";
                    WHEN "10000110" => D1<="11111100"; 
                    WHEN "10000111" => D1<="10000111";
                    WHEN "10001000" => D1<="11111111";
                    WHEN "10001001" => D1<="11100111";
                    WHEN OTHERS     => NULL;
                  END CASE;
                  CASE G2 IS
                    WHEN "00000000" => D2<="00111111";
                    WHEN "00000001" => D2<="00000110";
                    WHEN "00000010" => D2<="01011011";
                    WHEN "00000011" => D2<="01001111";
                    WHEN "00000100" => D2<="01100110";
                    WHEN "00000101" => D2<="01101101";
                    WHEN "00000110" => D2<="01111100";
                    WHEN "00000111" => D2<="00000111";
                    WHEN "00001000" => D2<="01111111";
                    WHEN "00001001" => D2<="01100111";
                    WHEN "10000000" => D2<="10111111";
                    WHEN "10000001" => D2<="10000110";
                    WHEN "10000010" => D2<="11011011";
                    WHEN "10000011" => D2<="11001111";
                    WHEN "10000100" => D2<="11100110";
                    WHEN "10000101" => D2<="11101101";
                    WHEN "10000110" => D2<="11111100"; 
                    WHEN "10000111" => D2<="10000111";
                    WHEN "10001000" => D2<="11111111";
                    WHEN "10001001" => D2<="11100111";
                    WHEN OTHERS     => NULL;
                  END CASE;
                  CASE G3 IS
                    WHEN "00000000" => D3<="00111111";
                    WHEN "00000001" => D3<="00000110";
                    WHEN "00000010" => D3<="01011011";
                    WHEN "00000011" => D3<="01001111";
                    WHEN "00000100" => D3<="01100110";
                    WHEN "00000101" => D3<="01101101";
                    WHEN "00000110" => D3<="01111100";
                    WHEN "00000111" => D3<="00000111";
                    WHEN "00001000" => D3<="01111111";
                    WHEN "00001001" => D3<="01100111";
                    WHEN "10000000" => D3<="10111111";
                    WHEN "10000001" => D3<="10000110";
                    WHEN "10000010" => D3<="11011011";
                    WHEN "10000011" => D3<="11001111";
                    WHEN "10000100" => D3<="11100110";
                    WHEN "10000101" => D3<="11101101";
                    WHEN "10000110" => D3<="11111100"; 
                    WHEN "10000111" => D3<="10000111";
                    WHEN "10001000" => D3<="11111111";
                    WHEN "10001001" => D3<="11100111";
                    WHEN OTHERS     => NULL;
                  END CASE;  
             end if; 
    end process;
      out0<=D0; out1<=D1; out2<=D2; out3<=D3;
end;