CYUSB306X

Document Number: 001-87516 Rev. *L

Page 32 of 37

4. Invalid PID Sequence in USB 2.0 ISOC data transfer.

When the CX3 device is functioning as a high speed USB device with high bandwidth isochronous endpoints, the PID sequence

of the ISO data packets is governed solely by the isomult setting. The length of the data packet is not considered while generating

the PID sequence during each microframe. For example, even if a short packet is being sent on an endpoint with MULT set to 2;

the PID used will be DATA2.

N/A

This condition is triggered when high bandwidth ISOC transfer endpoints are used.

ISOC data transfers failure.

This problem can be worked around by reconfiguring the endpoint with a lower isomult setting prior to sending short packets, and

then switching back to the original value.

No fix. Workaround is required.

5. USB data transfer errors are seen when ZLP is followed by data packet within same microframe.

Some data transfer errors may be seen if a Zero Length Packet is followed very quickly (within one microframe or 125 µs) by

another data packet on a burst enabled USB IN endpoint operating at super speed.

N/A

This condition is triggered in SuperSpeed transfer with ZLPs.

Data failure and lower data speed.

The solution is to ensure that some time is allowed to elapse between a ZLP and the next data packet on burst enabled USB IN

endpoints. If this cannot be ensured at the data source, the CyU3PDmaChannelSetSuspend() API can be used to suspend the

corresponding USB DMA socket on seeing the EOP condition. The channel operation can then be resumed as soon as the suspend

callback is received.

No fix. Workaround is required.