Velocity Reviews

Velocity Reviews (http://www.velocityreviews.com/forums/index.php)
-   VHDL (http://www.velocityreviews.com/forums/f18-vhdl.html)
-   -   Feedback mux created for signal data (http://www.velocityreviews.com/forums/t22808-feedback-mux-created-for-signal-data.html)

valentin tihomirov 08-31-2004 09:25 AM

Feedback mux created for signal data
 
Sinplify shows the following warnings

Feedback mux created for signal data[1:0]. Did you forget the set/reset
assignment for this signal?
Feedback mux created for signal data[3:0]. Did you forget the set/reset
assignment for this signal?
Feedback mux created for signal data[4:0]. Did you forget the set/reset
assignment for this signal?
Feedback mux created for signal data[7:0]. Did you forget the set/reset
assignment for this signal?



on this code:


architecture RTL of SHIFT_REGISTER is
signal DATA: STD_LOGIC_VECTOR(SIZE-1 downto 0);
begin
REG: process (CLK, RESET)
variable BitCnt: Integer range 0 to 8;
begin
if RESET = '1' then -- WARNINGS on this line
null;
DATA <= (others => '-');
elsif Rising_Edge(CLK) then
if ENABLE = '1' then
if LOAD = '1' then

-- VHDL not working for SIZE=1
-- DATA <= SIN & DATA (SIZE - 1 downto 1);

if SIZE = 1 then
DATA(0) <= SIN;
else
DATA <= SIN & DATA (SIZE - 1 downto 1);
end if;

end if;
end if;
end if;
end process REG;

POUT <= DATA;

end RTL;



trican 08-31-2004 12:04 PM

Re: Feedback mux created for signal data
 

Is this because you dont specify what what happens when enable and loa
equal 0. Though I could be wrong

--
trica
-----------------------------------------------------------------------
trican's Profile: http://www.totallychips.com/forum/member.php?userid=
View this thread: http://www.totallychips.com/forum/showthread.php?t=124


Thomas Stanka 09-01-2004 06:05 AM

Re: Feedback mux created for signal data
 
"valentin tihomirov" <valentin_NOSPAM_NOWORMS@abelectron.com> wrote

> if RESET = '1' then -- WARNINGS on this line
> null;
> DATA <= (others => '-');


Why do you use the null statement?

It seems that your synthesis tool didn't come along with reset to
don't-care. So use a dedicated set or reset. I bet your results will
be fine than.

bye Thomas


All times are GMT. The time now is 02:56 AM.

Powered by vBulletin®. Copyright ©2000 - 2013, vBulletin Solutions, Inc.
SEO by vBSEO ©2010, Crawlability, Inc.


1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57