Entity declaration

[marcif]

hello
please if i have the following entity declaration fo an 8 bits ACC suporting ALU operation :

entity ACC is
--generic contsnst
generic (Delay: Time := 10 ns)
--port declaration
port ( CLK, RESET: in bit ;
-- bla bla bla
CFLG, ZFLG, NFLG, OFLOW : in Bit
CFLG, ZFLG, NFLG, OFLOW : out Bit; -- zero,carry,negative and overflow falgs
); --??? how do i reserve the other 4 bits for later use?
end ACC;

note: i want to have an 8 bits ACC and an 8 bits flag register

Thanks

 

[vhdllearner]

I too am new to VHDL, but probably the following way would help u out...

entity ACC is
generic (Delay: Time := 10 ns)
port ( CLK, RESET: in bit ;
-- bla bla bla
CFLG, ZFLG, NFLG, OFLOW : in Bit --instead of this use
flags_in: in Bit_vector( 7 downto 0); -- and
flags_out: out Bit_vector( 7 downto 0); --and assign 4 of these 8 bits to ur flags... thus u will be saving the rest 4 for future use...

end ACC;

hope i have understood ur problem right...