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HUH, SAY WHAT? youself. If you are tired of explaining to us how ATA works, then stop. Of course, you would probably never post anything again.
I love poeple who rather than send a private email asking for clarification try to belittle people on public posts. Make them feel superior I assume.
DRQ=0
gary
----- Original Message ----- From: "Hale Landis" <[EMAIL PROTECTED]>
To: "T13 List Server" <[EMAIL PROTECTED]>
Sent: Monday, November 15, 2004 4:58 PM
Subject: Re: [t13] e04155r0 - DRQ=0 When ERR=1 Feature
This message is from the T13 list server.
[EMAIL PROTECTED] wrote:This message is from the T13 list server.
Example: is it is virtually impossible to clear DRQ at exactly the same time that ERR is set. Hence there will always be some sort of overlap where the state is undefined (DRQ -> 0 whiles ERR -> 1).
HUH? SAY WHAT?
[I sure wish we didn't have to spend so much time here talking about how ATA (especially PATA) works. :) ]
Please remember that a device is NOT ALLOWED to changed the state of DRQ or ERR while BSY=1. When a device sets BSY=0 it MUST HAVE DRQ AND ERR IN THE CORRECT STATE.
Is there some effort going on (that I don't know about) to completely redefine PATA? I ask because I've seen comments (that I have not responded to yet) concerning those BSY=1 loops in the state diagrams when a host is not using INTRQ (a polling host) - the comments I've seen show a complete lack of understanding of how PATA works since day one. Even though it is "off topic" I'll include my comment on this here... A device asserts INTRQ to say that it has moved from BSY=1 status to BSY=0 status (but not for all movements of BSY from 1 to 0) and when the host sees INTRQ asserted it should read the Status register (to acknowledge the INTRQ) -AND- if the host sees BSY=1 the device is BROKEN! No exceptions - the device is BROKEN! This applies to all commands including the EXEC DEV DIAG command.
So can we stop trying to redefine the most basic operational requirements of PATA (I don't care what you do with SATA)?
Hale
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++ Hale Landis ++ www.ata-atapi.com ++
