17 Jun
2011
17 Jun
'11
10:17 p.m.
On Fri, 17 Jun 2011, Chuck Guzis wrote:
Yes, but I don't see what that has to do with the
thread. If you're
going to dedicate a whole quad NAND package to a single 2-input-XOR,
that's not terribly efficient. Although probably every undergrad
computer logic professor has pointed out this "neat trick" in class
for the last 40+ years, I don't believe it's glitchless, so it's not
a really good choice.
By 'not glitchless' do you mean that if you simultaneously change the
inputs from 00 to 11 you'll see an approx. 1 gate delay wide transient on
the output of the XOR due to some of the signals passing through 2 and
some through 3 NANDs?
Is there a way to build an XOR from other types of gates that won't glitch
on any of the input transitions 00 <-> 11 or 10 <-> 01 ? Even if you can't
guarantee that all the gate delays are the same?
Alexey