Data sheet for MC6825

From: Holger Veit <holger.veit_at_ais.fhg.de>
Date: Mon Dec 15 14:27:54 2003

On Mon, Dec 15, 2003 at 11:21:10AM -0800, Vintage Computer Festival wrote:
> On Mon, 15 Dec 2003, Dwight K. Elvey wrote:
>
> > Does anyone have a data sheet for a Motorola MC6825?
> > I believe it is a USART but I can't find anything on
> > it. It is from the late 70's.
>
> I can only imagine at this point that it was a custom or internal part
> because I can't find any mention in any of my Motorola data books
> (several) nor the Master Selection Guide (1992).

Do you mean by chance the MC68HC25?

This is an I/O expander (port replacement) chip for various microcontrollers
such as the 146805E2, 6801, 6801U4, 6803, 6803U4 and 68HC11.
It comes in a 52 pin PLCC package.

Its purpose is to provide the I/O ports of a microcontroller that get "lost"
if the system is expanded with external ROM/RAM (some ports of these uCs then
are used as the data bus and the multiplexed address bus).

The data sheet I have is from 1990, not 1970's, though.

Holger
Received on Mon Dec 15 2003 - 14:27:54 GMT