Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!husc6!rutgers!cbmvax!daveh
From: daveh@cbmvax.UUCP (Dave Haynie)
Newsgroups: comp.sys.amiga.tech
Subject: Re: Longword alignment with 68020
Message-ID: <6031@cbmvax.UUCP>
Date: 21 Feb 89 18:28:36 GMT
References: <712@cord.UUCP>
Distribution: na
Organization: Commodore Technology, West Chester, PA
Lines: 22

in article <712@cord.UUCP>, nsw@cord.UUCP (Neil Weinstock) says:

> Quickie question:

> Do the 68020/32-bit memory boards (ala A2620) require that longword data
> be longword-aligned?  I suspect that they do, but I want to be sure.

No, actually, the 68020 is less demanding about word alignment than the 
68000.  It wants instructions word aligned, but data doesn't have to be
aligned at all.  However, if a longword datum isn't longword aligned, the
'020 will take two cycles to get at it, which will of course make fetching
that thing 1/2 as fast as it could be.


> / Neil Weinstock | att!cord!nsw     | "One man's garbage is another     \
> \ AT&T Bell Labs | nsw@cord.att.com | man's prune danish." - Harv Laser /


-- 
Dave Haynie  "The 32 Bit Guy"     Commodore-Amiga  "The Crew That Never Rests"
   {uunet|pyramid|rutgers}!cbmvax!daveh      PLINK: D-DAVE H     BIX: hazy
              Amiga -- It's not just a job, it's an obsession