Multiple Command Sequence in USB3

[Tom Friend]

* From the T10 Reflector (t10 at t10.org), posted by:
* Tom Friend <TomF at illuminosi.com>
*
It is my understanding that each command transmission is an atomic operation.
That is why you found no such example. Please do not intermix the
transactions as that will  potentially confuse some devices.
Having said that, what you ask of the HC and what it may really do under high
traffic conditions can be very different.
Thomas Friend
Technical Liaison Manager
PLX Technology Inc.
(aka Oxford Semiconductor)
+1 (360) 860-1831      US mobile
+44 (0)7539 55 03 54  UK mobile
tom.friend.oxsemi	Skype
-----Original Message-----
From: Madhukar <madhukar.gubba at gmail.com>
Sent: Tuesday, June 22, 2010 3:22 PM
To: t10 at t10.org <t10 at t10.org>
Subject: Multiple Command Sequence in USB3
* From the T10 Reflector (t10 at t10.org), posted by:
* Madhukar <madhukar.gubba at gmail.com>
*
Hi All,
I have gone through the UASP specification. However, I did not find
any sequence diagram which illustrates the multiple (not
bidirectional) commands scenario. So, I followed the UAS
specification, which has a sequence diagram for multiple command
scenario. According to that, I should issue multiple COMMAND IUs and
wait for a callback before actually transmitting the data. But, in the
UASP specification, it says I should submit the SENSEIU, followed by
DATA, which is followed by COMMAND IU. So, I am little confused on the
multiple command scenario. My current implementation in host side has
the below mentioned sequence.
Current Case
•	Submit SENSE IU for Tag 1
•	Submit DATA for Tag1
•	Submit COMMAND IU for Tag1
•	Submit SENSE IU for Tag 2
•	Submit DATA for Tag2
•	Submit COMMAND IU for Tag2
•	Received ACK for COMMAND IU of Tag2
•	Received DATA transfer complete callback of Tag2
•	Received SENSEIU complete callback of Tag2
………………………same for Tag1
Is this sequence appropriate? or should it be like this
Theoretical Alternative
•	Submit COMMAND IU for Tag1
•	Submit COMMAND IU for Tag2
•	Received ACK for COMMAND IU of Tag2
•	Submit DATA for Tag2
•	Received DATA transfer complete callback of Tag2
•	Submit SENSE IU for Tag 2
•	Received SENSEIU complete callback of Tag2
………………………same for Tag1
Thanks in advance.
Thanks and Regards,
Madhukar
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