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Message
From: "Vikas T Rao " <vikasraot@m...>
Date: Mon, 05 Aug 2002 13:57:03 +0530
Subject: Re: [usb] Usb Transactions on the pipes
** Proprietary **
hi,
the host transactions to the endpoints within same device can't be inter-leaved in any of USB verisons(1.0/1.1/2.0). only in USB2.0, it can be possible to inter-leave to the endpoints within different devices. in USB1.1 or 1.0, nothing above is possible.
if the host is not abiding by the above rules, then it's not USB compliant. behavior of the device during those situations is unknown.
hope i am correct.
...vikas.
>>> govindsrajan@h... 08/04/02 03:02AM >>>
Hi,
Can the usb host transactions be inter-weaved ? For example,
can the host send packets to another endpoint in between
the packets of current endpoint? The following sequence is shown
below.
1. Setup Token (Control Pipe) Host
2. Data Pkt (Control Pipe) Host
3. Out Token (BulkOut Pipe) Host
4. Data Pkt (BulkOut Pipe) Host
5. Out Token (BulkOut Pipe) Host
6. Data Pkt (BulkOut Pipe) Host
7. Handshake Pkt (Control Pipe) Device
8. Handshake Pkt (BulkOut Pipe) Device
After #2, device is supposed to send a ACK/NAK/STALL Pkt
if the previous data pkt went thru succesfully. Before teh device
sends the pkt, can the usb host send some other pkt to another
endpoint. What is the behaviour of the device in such a case.
Cd anyone pl. clarify.
Govind
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