About LPC1347 USB endpoint communication issues

[niupi_plus]

When we developed the USB driver of lpc1347, we found that the OUT interrupt of endpoint 2 can only be triggered once, and the packet capture found that the second trigger is abnormal. Figure 1 shows the correct response after Endpoint 2 normally receives the host OUT transaction.

The transaction for OUT at Endpoint 2 is configured to be of type bulk out. Figures 3 and 4 show the source code configured when endpoint 2out interrupts the call.

[Alice_Yang]

Hello @niupi_plus 

The issue of the OUT interrupt for Endpoint 2 triggering only once may be caused by the following reasons.

• Ensure the interrupt flag for Endpoint 2 is properly cleared in the interrupt handler. Failure to clear the flag can prevent subsequent interrupts from triggering.
• Verify that the buffer for Endpoint 2 is released and reconfigured after each transaction. An unreleased buffer can block further data transfers.
• Review the USB controller configuration to ensure Endpoint 2 is properly enabled and configured for Bulk OUT transactions.
• Use a USB protocol analyzer to confirm that the host is sending the OUT transactions correctly. 

BR

Alice