Re:Programming ARM μC in Rust at four different levels of ab...
by posterboy on Thursday February 22, 2018 @08:03PM
(#16443252)
I think in the old days, before CMOS, this was called open-collector. I had learned about it in first semester digital logic not too long ago playing with the "high speed" 7400 series. If I remember correctly, the latch needs to support the open collector capability, but the reason escapes me.
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Re:Programming ARM μC in Rust at four different levels of ab...
by dbcurtis on Friday February 23, 2018 @03:06PM
(#16449041)
Open collector if you have a bipolar technology. Modern microcontrollers are CMOS, so the pull-down transistor has a drain, not a collector. TTL is bipolar, so the transistor has a collector.