Re: Strange 8255 behavior

From: Michał Pleban <lists_at_michau.name>
Date: Mon, 18 Jun 2018 19:01:27 +0200
Message-ID: <5B27E567.4060004@michau.name>
Hello!

Ruud@Baltissen.org wrote:

> But if an output and input are connected to each other, is that still 
> the case? I can imagine that a cell used for an emulated output can
> be used for the emulated input as well.

This is generally true, if the pin is unidirectional; for bidirectional
pins, you still need both macrocells. However, in the situation on the
8088 card (when the whole data port has always the same direction) you
can save on the cells for DDR.

Also, of course you still need macrocells for the D0..D7 lines.

Regards,
Michau,
Received on 2018-06-18 20:00:04

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