Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ulowell!m2c!wpi!jhallen
From: jhallen@wpi.wpi.edu (Joseph H Allen)
Newsgroups: comp.sys.m6809
Subject: Re: fast clock for 6809
Message-ID: <1984@wpi.wpi.edu>
Date: 20 Apr 89 22:10:18 GMT
References: <1605@ccnysci.UUCP>
Reply-To: jhallen@wpi.wpi.edu (Joseph H Allen)
Organization: Worcester Polytechnic Institute, Worcester, MA. USA
Lines: 12

In article <1605@ccnysci.UUCP> jhuang@ccnysci.UUCP (Jian Huang) writes:
>
>version available? We ran that chip at 3 mhz wihtout any
>problem. But I don't know the long-term effect to the
>system. Does anyone have such experience on this?

I think it's safe for the processor to do this (you have to go quite fast for
the processor itself to start screwing up (I've seen 1Mhz parts run at 2Mhz)).
But, take a look at the bus timing:  The set-up and hold times remain the
same no matter what speed the processor is running at.  So if you increase the
processor speed, the peripheral access time must be much faster than if you
used a higher speed part at that same speed.