demulti4_1.tdf

d_clck的VHDL语言编程

SUBDESIGN  demulti4_1 
(
   S[2..0],I[3..0]  :INPUT ;
    SA[3..0],SB[2..0],MA[3..0],MB[2..0],HA[3..0],HB : OUTPUT;
)
BEGIN 
CASE S[] IS
    WHEN 0=>
       SA[3..0] = I[3..0];
    WHEN 1=>
       SB[2..0] = I[2..0];
    WHEN 2=>
       MA[3..0] = I[3..0];
    WHEN 3=>
       MB[2..0] = I[2..0];
    WHEN 4=>
       HA[3..0] = I[3..0];
    WHEN 5=>
       HB = I[0];
    WHEN OTHERS =>
       SA[3..0]=0;SB[2..0]=0;
       MA[3..0]=0;MB[2..0]=0;
       HA[3..0]=0;HB=GND;
END CASE;
END;