notgate.vbe

i need of vhdl code for 32-bit risc processor

ENTITY notgate IS
PORT (
a4 : IN BIT;
c4 : OUT BIT
);
END notgate;

ARCHITECTURE not_arch OF notgate IS

BEGIN
with a4 select
c4 <= b"0" when b"1",
       b"1" when b"0" ;
END;