Re: Strange 8255 behavior

From: Michał Pleban <*lists_at_michau.name*> Date: Mon, 18 Jun 2018 19:04:05 +0200 Message-ID: <5B27E605.6040607@michau.name> · lists_at_michau.name

Mia Magnusson wrote:

> The register map is unfortunitely made in a way that it won't be a
> great idea to split it so one CPLD handle the odd addresses and the
> other the even addresses.

You are not required to split it by even/odd addresses. You can split it
as you like, as long as you supply all address pins to both CPLDs (you
can even have more than two if you really want). You will just need a
(yest unspecified) number of additional lines between the CPLDs so that
they can communicate (for example, the CPLD where the TOD is impemented
must comunicate the alarm to the CPLD which implements the interrupt logic).

Regards,
Michau.