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Hi Hale, What exactly is it that you think is missing? Clause 6.6.2.3 in ATA/ATAPI-6 provides an excellent overview of Ultra DMA burst termination phase rules (even if I do say so myself). The content of this clause has been in every A/A standard since the introduction of Ultra DMA. This clause reads: 1) Either a sender or a recipient may terminate an Ultra DMA burst. 2) Ultra DMA burst termination is not the same as command completion. If an Ultra DMA burst termination occurs before command completion, the command shall be completed by initiation of a new Ultra DMA burst at some later time or aborted by the host issuing a hardware or software reset or DEVICE RESET command if implemented by the device. 3) An Ultra DMA burst shall be paused before a recipient requests a termination. 4) A host requests a termination by asserting STOP. A device acknowledges a termination request by negating DMARQ. 5) A device requests a termination by negating DMARQ. A host acknowledges a termination request by asserting STOP. 6) Once a sender requests a termination, the sender shall not change the state of STROBE until the recipient acknowledges the request. Then, if STROBE is not in the asserted state, the sender shall return STROBE to the asserted state. No data shall be transferred on this transition of STROBE. 7) A sender shall return STROBE to the asserted state whenever the sender detects a termination request from the recipient. No data shall be transferred nor CRC calculated on this edge of DSTROBE. 8) Once a recipient requests a termination, the responder shall not change DMARDY from the negated state for the remainder of an Ultra DMA burst. 9) A recipient shall ignore a STROBE edge when DMARQ is negated or STOP is asserted. If this isn't sufficient, excruciating detail on exactly what is supposed to happen in each specific case of Ultra DMA burst termination is provided in clauses 9.13 and 10.2.4. If, after reading these clauses, you have any additional questions about Ultra DMA burst termination, please feel free to call or send an email to me. In addition, I have found that using the "find" function in Word or Acrobat is most helpful when looking for specific details about something like this in these documents. Regards, Mark Evans Maxtor Corporation 500 McCarthy Boulevard Milpitas, CA 95035 USA Tel: 408-894-5310 Cell: 408-391-7805 FAX: 408-324-7432 email: [EMAIL PROTECTED] -----Original Message----- From: Hale Landis [mailto:[EMAIL PROTECTED]] Sent: Monday, November 26, 2001 7:51 AM To: T13 List Server Subject: Re: [t13] Command completion of an UDMA OUT burst ... This message is from the T13 list server. On Fri, 23 Nov 2001 18:36:46 +0100, Stephane Cattaneo wrote: >I have a question regarding the completion of a burst in udma out. >Who has to do the termination protocol ? The device or the host ? Here again is an example of something that is missing from the ATA/ATAPI-x documents. I have lost count of the number of times this question has been posted to the T13 list server. Anyone want to attempt to provide the missing information? Anyone know where the missing information should go in the document? *** Hale Landis *** [EMAIL PROTECTED] *** *** Niwot, CO USA *** www.ata-atapi.com *** Subscribe/Unsubscribe instructions can be found at www.t13.org. Subscribe/Unsubscribe instructions can be found at www.t13.org.
