Re: 6522 VIA inputs

Date: Sat, 22 Apr 2017 16:35:38 +0200
Message-ID: <32463727.ZyOev5cdaR@rakete>
On Friday 21 April 2017, 21:40:17 wrote:
> > It's perfectly acceptable to ignore the pull ups and drive 0v/5v.
> I am not sure if I am not trying to overengineer but what causes my doubts
> is that it's never 0V/5V, and especially never the same between different
> families of devices, etc.  While pushing the (pulled-up) line LO is OK
> because that's what it is meant to be done, the potential of the sourcing
> output and the pulled-up line are almost certainly different so it will
> have to cause some (unnecessary / unnecessarily higher) current flow
> through the line, possibly adding to consumption, unwanted emissions, etc.
> ... or are all those possible side-effects fully negligible and I am just
> too paranoid here? ;-)

driving a NMOS i/o line high is a big nono. just dont. its a common thing to 
do to connect several outputs together, forming a wired OR - when one of those 
outputs is driving high, the one trying to pull low will have a hard time 
doing it. even if it still may work, the signal timing will go poop


Democracy, n.: The triumph of popularity over principle.

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Received on 2017-04-22 15:00:02

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