On Friday 21 April 2017, 21:40:17 firstname.lastname@example.org 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 -- http://www.hitmen-console.org http://magicdisk.untergrund.net http://www.pokefinder.org http://ar.pokefinder.org Democracy, n.: The triumph of popularity over principle. Message was sent through the cbm-hackers mailing listReceived on 2017-04-22 15:00:02
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