[A89] Re: Setting bit fields

[A89] Re: Setting bit fields

• To: <assembly-89@lists.ticalc.org>
• Subject: [A89] Re: Setting bit fields
• From: "Scott Noveck" <noveck@pluto.njcc.com>
• Date: Thu, 28 Feb 2002 15:50:20 -0500
• References: <20020228192531.9230318046@mx-1.sollentuna.net>
• Reply-To: assembly-89@lists.ticalc.org

> I want to change some things in the I/O ports. $600015. But i dont want to
> change all bits. What is the most used way to do this?
> ...
> AND all bits to be reset with 0 and OR the bits to be set with 1? Or
> should I just move a byte over there?

Yup, you should only need two total instructions -- one AND, one OR.  You
can AND multiple bits in one instruction by ANDing the entire byte with a
mask (want to reset all but bit 6?  AND the byte with 0xBF); same thing with
OR.

    -Scott

• [A89] Re: Setting bit fields
• From: "Sebastian Reichelt" <SebastianR@gmx.de>
• [A89] Re: Setting bit fields
• From: Olle Hedman <alh@home.se>

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