Article View: comp.sys.atari.st
Article #22997Re: 030 sync cycles (was : A1200 versus Falcon 030 once again)
From: Glen Sescila
Date: Fri, 22 Jan 1993 13:25
Date: Fri, 22 Jan 1993 13:25
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1638 bytes
In article <1982@enst.enst.fr> elendir@inf.enst.fr writes:
>Joern Moe writes
>] In the falcon they use sync
>] mode on a 16 bit bus. This gives a 4 clock cycle for each longword
>] access to the bus. This implies a 25% reduction in performance, not 50%.
>
> That is wrong. Synchrone cycles on the 68030 (i.e. those terminated by STERM
>rather than DSACK) must be 32-bit wide. Refer to the 030 User s Manual. There
>is no other way than DSACK to end a 16-bit wide exchange.
>
>Vincent.
That is wrong. The external hardware (external to the cpu) could do 2 16
bit cycles and pack them into 1 32 bit. I'm not saying thats what the Falcon
does but be careful when you use words like 'never' and 'no other way'.
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"Now You're Playing With Power Without The Price!" Glen Sescila |||
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My opinions do not necessarily reflect those of my employer and probably are
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Path: arc1-ca.pugleaf.net!sparky!uunet!cs.utexas.edu!natinst.com!natinst.com!not-for-mail From: glens@natinst.com (Glen Sescila) Newsgroups: comp.sys.atari.st Subject: Re: 030 sync cycles (was : A1200 versus Falcon 030 once again) Date: 22 Jan 1993 07:25:44 -0600 Organization: National Instruments, Austin, TX Lines: 22 Message-ID: <1joskoINNqm@falcon.natinst.com> References: <H.6a78NGVZTA2@fredrik.atari.no> <1982@enst.enst.fr> NNTP-Posting-Host: falcon.natinst.com Keywords: STERM