Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!lll-winken!uunet!cbmvax!bryce
From: bryce@cbmvax.UUCP (Bryce Nesbitt)
Newsgroups: comp.sys.m68k
Subject: Re: 68020 cache
Message-ID: <6669@cbmvax.UUCP>
Date: 21 Apr 89 20:37:53 GMT
References: <1835@aucs.UUCP>
Reply-To: bryce@cbmvax.UUCP (Bryce Nesbitt)
Distribution: na
Organization: Commodore Technology, West Chester, PA
Lines: 22

In article <1835@aucs.UUCP> 870646c@aucs.UUCP (Barry Comer) writes:
>...but I was wondering
>if the cache on the 68020 is normally active or does the programmer
>have to turn it on???

The 68020 instruction cache defaults to OFF at external reset (or power on).

In the specific case of the Amiga OS, the Executive detects the 68020, and
turns on the cache.  Programmers may query the system for the CPU type,
but generaly there is no need to.

	-Bryce Nesbitt, Commodore-Amiga, Inc.


Note that the RESET *instruction* does not disable the cache, MMU or FPU.  This
can make a soft reboot just a bit trickier to write :-).
-- 
|\_/|  . ACK!, NAK!, EOT!, SOH!
{O o} .     Bryce Nesbitt, Commodore-Amiga, Inc.
 (")        BIX: bnesbitt
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