Path: utzoo!attcan!uunet!ginosko!brutus.cs.uiuc.edu!tut.cis.ohio-state.edu!unmvax!pprg.unm.edu!topgun.dspo.gov!lanl!cmcl2!phri!roy
From: roy@phri.UUCP (Roy Smith)
Newsgroups: comp.arch
Subject: Re: Parity in Internal Data Paths of Processors
Keywords: parity, error detection
Message-ID: <3983@phri.UUCP>
Date: 8 Sep 89 13:22:40 GMT
References: <124311@sun.Eng.Sun.COM>
Reply-To: roy@phri.UUCP (Roy Smith)
Organization: Public Health Research Inst. (NY, NY)
Lines: 15

In <124311@sun.Eng.Sun.COM> kum@sccmts.Sun.COM (Kumar Venkatasubramaniam):
> does anyone know of parity being carried through the internal paths of a
> processor?

	The AT&T 3B20D does.  This was (is?) the machine which drives the
5ESS phone switches.  Every internal data path is parity checked or
duplicated and compared in places where parity is impractical, like the ALU
(I don't know of any way to calculate the parity of, for example, an
integer multiply).  There was a special issue of BSTJ on it about 5-10
years ago.
-- 
Roy Smith, Public Health Research Institute
455 First Avenue, New York, NY 10016
{att,philabs,cmcl2,rutgers,hombre}!phri!roy -or- roy@alanine.phri.nyu.edu
"The connector is the network"