Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!oakhill!billl
From: billl@oakhill.sps.mot.com (Bill Ledbetter)
Newsgroups: comp.arch
Subject: Re: 040 vs 030 SPEC nos.
Message-ID: <1991May28.183453.13821@oakhill.sps.mot.com>
Date: 28 May 91 18:34:53 GMT
References: <181@armltd.uucp>
Distribution: comp
Organization: Motorola Inc., Austin, Texas
Lines: 24

abaum (Allen Baum) writes:

>I'm sorry to disappoint you, but the 68040 runs effectively a half
>speed bus. A 25Mhz '040 is running at 50Mhz internally. There are,
>in fact, two clock pins, one at 25Mhz, and one at 50. For comparison,
>you should be comparing 50Mhz '030s and 25Mhz '040s.

Well, in general, an 040 at 25MHz runs both the internals (caches, ALUs,
etc.) and the external bus at 25MHz: the 50MHz input is used to get timing
edges.  In general, a 25MHz 030 runs the internals at 12.5MHz and the
external bus at 25Mhz.

---------------------------------------------------------------------------
Bill Ledbetter
Motorola Inc.    MD OE37                 email: cs.utexas.edu!oakhill!billl
6501 William Cannon Dr. West
Austin, TX 78735-8598


-- 
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Bill Ledbetter
Motorola Inc.    MD OE37                 email: cs.utexas.edu!oakhill!billl
6501 William Cannon Dr. West