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From: hammond@petrus.UUCP (Rich A. Hammond)
Newsgroups: net.arch
Subject: Re: The problem with high-order truncation of multiplication
Message-ID: <441@petrus.UUCP>
Date: Mon, 5-Aug-85 07:17:54 EDT
Article-I.D.: petrus.441
Posted: Mon Aug  5 07:17:54 1985
Date-Received: Tue, 6-Aug-85 10:32:05 EDT
References: <846@turtlevax.UUCP>
Organization: Bell Communications Research, Inc
Lines: 16

> Ken Turkowski @ CADLINC, Menlo Park, CA says:
> discussion of multiplication of fixed point where MS half is important...
> 
> Machines like the WE32100 which automatically truncate products at the top
> cannot be used for signal processing.  I'm surprised that AT&T would make
> such a machine, since they do so much signal processing for echo cancelling,
> phase extraction, etc. in their communication products.
> 
But almost all signal processing to be done in real time is much too slow
on even a 32 bit micro.  They have had specialized chips to do digital
signal processing for many years, and the echo cancelling chip is a full
custom design.
Besides, the processor people are probably a completely different location
and organization than the people building applications for signal processing.
Rich Hammond (Bell Commmunications Research, not part of AT&T).
(ihnp4, decvax, ucbvax)!bellcore!hammond