This message is from the T13 list server.

On Fri, 10 Sep 2004 21:39:53 +0900, [EMAIL PROTECTED]
wrote:
>This message is from the T13 list server.
>(1) No one should drive  DD15-8 during register reads.
>(2) Many host systems pull the ATA DDx signals high.
>None of this is in the standard document, but...
>If (1) is true, shouldn't it be MANDATORY for the host
>to pull up the DD15-8 ?

This is a design issue for the host system. The host system could
pull DDx up or down - that has no effect on how the ATA interface
operates (the DDx signals are Tri-State). This is much like the INTRQ
signal - some hosts pull it high, some hosts pull it low - some hosts
are level triggered and some are edge triggered - none of this
effects how the ATA interface operates - these are just internal host
design issues.

Hale


*** Hale Landis *** www.ata-atapi.com ***



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