Can I do this?

[logitech]

Hi!
Can I do this:

if (flag = '1') then
flag <= '0';
....

Thanks!

 

[Mike Treseler]

logitech wrote:

Can I do this:
if (flag = '1') then
flag <= '0';

You can do it, but it may not do
what you expect, because the
value of flag is still '1'
until the end of the process.
(which often means the next clock cycle)

If I use a process variable instead of a signal
I would get an immediate update:
if flag_v = '1' then
flag_v := '0';
end if
-- flag value is '0' below here
....

But for internal nodes, this
is the same as just saying:

flag_v := '0';

I use boolean variable handshakes like this frequently
in single process entities.
Note that when I update such a flag,
the code below will see it on the the
same clock tick, but code above won't
see it until next tick.

-- Mike Treseler