4 Sep
2011
4 Sep
'11
7:10 a.m.
It may be the chip, but what are the control
inputs doing? Pin 15 is a
global
enable to that chip, if it's high, the chip
is disabled, and all ouptus
are forced
high (IIRC). Often this is not used, and pin 15
is tied to ground, but
it's best to
check.
Pin 1 selects between the 1 possible inputs for each multiplexer section.
Is this in the right state to pass the data through?
Just checked the printset, that shows pin 15 tied to ground. Good job really because I have already ordered the part! Thanks for
telling me though, I
will have to be more careful next time.
The expression 'GIGO' applies to logic gates (and other devices) as much
as to complete computers :-). If the input conditons aren't right, the
output won't be right either, even if the chip is working perfectly.
-tony