From: Neil Cherry <ncherry@linuxha.com>
To: Microcontroller discussion list - Public. <piclist@mit.edu>,
	madscientistatlarge <madscientistatlarge@protonmail.com>
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Date: Mon, 5 Oct 2020 05:21:55 -0700
Subject: Re: [EE] Using a microcontroller as a peripheral?
Thread-Topic: [EE] Using a microcontroller as a peripheral?
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On 10/5/20 1:56 AM, madscientistatlarge wrote:

> It depends on what you consider "a peripheral chip", i.e. embedded and co=
ntrolled by an
> external cpu, or do you mean using as a peripheral for some special funct=
ion (like the
> soft power control on motherboards).  Do you include things like ethernet=
 cards that
> handle checksums/encryption to unload the main cpu?  And of course the PI=
C=20
> microcontrollers were originally for I/O expansion of other micros or pos=
sibly larger=20
> systems with a higher end cpu?  Burglar alarms with central monitoring wo=
uld also=20
> likely be included if they are not ancient (I.E. the burglar/fire alarm h=
as a micro,=20
> and the Monitoring station uses desktops and/or servers for the monitorin=
g).

My apologies, I did make that way too vague. Let me add specifics. I want t=
o use a PIC32
as a peripheral chip like an 8255 and a 6850 and interfacing that to an exi=
sting
microprocessor chip as a 6502, 6809 or Z180. I happen to have these boards,=
 which is
why I'm selecting these. This would be a parallel, 8 bit interface with add=
ressing
and control for accessing registers. I'm trying not to rewrite the firmware=
 on
these old boards.

And yes I do see the irony of taking a chip infinitely more powerful than t=
he main
CPU and turning it into a peripheral. But I want to start off with simple (=
the
8255) and work to more complex (video chips) which really need to connect t=
o HDMI
now.

Oh, this is a side project. Not something for work.

So far my Search-fu has me running running into the peripherals of the MCU =
not
the MCU a peripheral of the CPU.

--=20
Linux Home Automation         Neil Cherry       ncherry@linuxha.com
http://www.linuxha.com/                         Main site
http://linuxha.blogspot.com/                    My HA Blog
Author of:    	Linux Smart Homes For Dummies
--=20
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