Subject: Re: Nubus card debugging
To: David A. Gatwood <dgatwood@gatwood.net>
From: Daniel R. Killoran,Ph.D. <drk@shore.net>
List: port-mac68k
Date: 08/04/2002 11:07:45
David A. Gatwood wrote:
>
>And why does this code appear to read from the same hardware address
>several times in a row? Is that by design, or did I break something while
>porting it? (or both... :-)
>
"Reading" a hardware address is not always done with the intention of
obtaining its contents. Often it is done to clear a flag. This will
often be the case when the address is that of a hardware register on
the board.
Alternatively, it might be waiting for a flag to be raised.
Dan Killoran