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From: davet@oakhill.UUCP (Dave Trissel)
Newsgroups: comp.sys.m68k
Subject: Re: ADDA.L (SP)+,SP  (68020)
Message-ID: <1052@oakhill.UUCP>
Date: Wed, 2-Dec-87 16:00:00 EST
Article-I.D.: oakhill.1052
Posted: Wed Dec  2 16:00:00 1987
Date-Received: Sat, 5-Dec-87 17:41:57 EST
References: <407@palladium.UUCP>
Reply-To: davet@oakhill.UUCP (Dave Trissel)
Organization: Motorola Inc. Austin, Tx
Lines: 21
Keywords: MC68020

In article <407@palladium.UUCP> nw@palladium.UUCP (Neil Webber) writes:
>Is the following instruction sequence an "undefined" operation?
>
>        ADDA.L  (SP)+,SP
>

No, this is well defined.  The stack register value is first incremented by
four and then totally replaced by the memory source data.

>        MOVES.x An,(An)+
>            or
>        MOVES.x An,-(An)
>
>        where An is the same address register for both source and destination
>        operand is an undefined operation.
>
>Is this meant to be a generic warning or only for MOVES?  ...

This warning only pertains to the MOVES instruction.

 -- Dave Trissel - Motorola Austin  - ihnp4!ut-sally!im4u!oakhill!davet