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ARC-OTG USB question

Hi everyone,

I'm working on a linux device driver for an Arm based USB device. I've got an ARC-OTG USB controller and an ISP1504 compatable transciever. I'm trying to find out how to switch from full speed to high speed when the host starts negotiation. I've looked through the USB controller data sheet, and I dont see anything that allows me to change speed, besides test mode. Is the controller responsible for doing the speed negotiation? Or does the driver code handle this itself? I've looked through other driver code for the ARC-OTG block with no luck. Any suggestions would be greatly appreciated. Thanks.

Lee

Reply to
Lee Thalblum
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Op Fri, 05 Jun 2009 16:22:33 +0200 schreef Lee Thalblum :

"Transition to high-speed signaling is accomplished by means of a low level electrical protocol which occurs during Reset." - Universal Serial Bus Specification Revision 2.0, paragraph 7.1.7.3 "Connect and Disconnect Signaling"

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Reply to
Boudewijn Dijkstra

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Yes, I've read the spec and understand the protocol. My question is, is this handled by the ccontroller, or does the driver have to handle this in software? I dont see anything in the controller data sheet that addresses this either way.

Reply to
Lee Thalblum

I expect both ARC and your USB protocol analyzer to be able to provide the necessary information.

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Reply to
Boudewijn Dijkstra

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