How to know if USB data buffer is completely transmitted ?

[_Ferrari_]

I am developing an application based on the LCP5526 microcontroller. From USB,configured as VCOM, I need to receive and transmit a large amount of data (size>20kbyte). The size of the USB buffer is 64 bytes, so I would like to know:

- what happens if I receive a data amount greater than 64 bytes
- to transmit data, I need to fragment my buffer (called BUFFER A) into multiple parts (called BUFFER B[0], B[1], B[2], ..., B[n]) and transmit them separately. How do I know that a buffer (B[i]) has been completely transmitted before moving on to the next (B[i+1])?

Has anyone of you had a similar problem? In that case, how was it solved? Thank you very much for your help and collaboration Best regards

[gauravsharma7]

You can configure USB interrupt that routes to NVIC on LPC552x. Whenever you receive data in USB buffers, the handler gets called. You might find this helpful - https://github.com/nxp-mcuxpresso/mcux-sdk-middleware-usb/blob/main/docs/MCUXpresso%20SDK%20USB%20St...

There are callbacks that can be configured which are called when you transmit or receive data on USB buffers.