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USB Low-Full-High Speed Peripherals

Anonymous
Not applicable

Hi,

I'm task with figuring out, why our USB communication randomly is in-stable. In a USB trace I was able to locate the following strange behavior, where the ACK on the setup package seams very late (see image below). I was wondering, under which circumstances is such a behavior can be expected?

pastedImage_0.png

I'm relative new to such low level debugging and would welcome any hints.

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1 Solution
SrinathS_16
Moderator
Moderator

Hello,

- What is the request that is sent to the device (bRequest = 0x00 from trace). Please explain what this request corresponds to.

- Please let us know the USB class that the device conforms to.

- From the trace, it can be seen that there is no ACK from the device. Kindly, ensure that the class specific request (0x00) is handled in the device's firmware.

EDIT:

- When designing a class specific device, the requests specific to that class ought to be handled in the firmware appropriately.

Best regards,

Srinath S

View solution in original post

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1 Reply
SrinathS_16
Moderator
Moderator

Hello,

- What is the request that is sent to the device (bRequest = 0x00 from trace). Please explain what this request corresponds to.

- Please let us know the USB class that the device conforms to.

- From the trace, it can be seen that there is no ACK from the device. Kindly, ensure that the class specific request (0x00) is handled in the device's firmware.

EDIT:

- When designing a class specific device, the requests specific to that class ought to be handled in the firmware appropriately.

Best regards,

Srinath S

View solution in original post

0 Likes