🚀 go-pugleaf

RetroBBS NetNews Server

Inspired by RockSolid Light RIP Retro Guy

Article View: comp.sys.amiga.tech
Article #3113

Re: 2630 Data Cache

#3113
From: markv
Date: Wed, 28 Mar 1990 18:04
27 lines
1756 bytes
> That's the best thing anyone could have done under 1.3 to support data
> caching, but won't help on a machine with external cache or a 68040.

But it wont be a problem on a 68040.
 
> Anyway, some cache configurations allow line or block flushes.  Others may
> actually snoop the bus in hardware in one of several ways and make the
> flush unecessary.

The 68040 does this both ways.  It snoops the bus for accesses to
memory it has cached.  If it is a write access, it turns around and
marks those cache entries invalid, it senses a read access, it
inhibits the read cycle and takes it over, putting out the cached
value for whatever is trying to read it (or flushing the entries).

Of course this only works on machines that fully implement the 68040s
cache and bus control lines.

-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Mark Gooderum			Only...		\    Good Cheer !!!
Academic Computing Services	       ///	  \___________________________
University of Kansas		     ///  /|         __    _
Bix:	  markgood	      \\\  ///  /__| |\/| | | _   /_\  makes it
Bitnet:   MARKV@UKANVAX		\/\/  /    | |  | | |__| /   \ possible...
Internet: markv@kuhub.cc.ukans.edu
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Technical Details
Message-ID: <22630.2610a837@kuhub.cc.ukans.edu>
Path: arc1-ca.pugleaf.net!utzoo!attcan!uunet!cs.utexas.edu!wuarchive!kuhub.cc.ukans.edu!markv
References: <345@hawk.isc-br.com> <10121@cbmvax.commodore.com> <10158@cbmvax.commodore.com> <10208@cbmvax.commodore.com>

Show Full Headers
Complete Article Headers
Path: arc1-ca.pugleaf.net!utzoo!attcan!uunet!cs.utexas.edu!wuarchive!kuhub.cc.ukans.edu!markv
From: markv@kuhub.cc.ukans.edu
Newsgroups: comp.sys.amiga.tech
Subject: Re: 2630 Data Cache
Message-ID: <22630.2610a837@kuhub.cc.ukans.edu>
Date: 28 Mar 90 18:04:07 GMT
References: <345@hawk.isc-br.com> <10121@cbmvax.commodore.com> <10158@cbmvax.commodore.com> <10208@cbmvax.commodore.com>
Organization: University of Kansas Academic Computing Services
Lines: 27