Datasheet

Figure 9. Token done interrupt processing
The endpoint callback function includes two types: control endpoint callback function and non-control endpoint callback function.
If the current endpoint is a control endpoint, the control endpoint callback function is called; if the current endpoint is a non-control
endpoint, the non-control endpoint callback function is called. The callback function of the control endpoint implements the
processing of standard and class requests; the non-control endpoint callback function implements the data transmission function,
and transmits the data received by the Bluk OUT endpoint to the host through the Bluk IN endpoint. The non-control endpoint
callback functions for the 15 VCOMs in this application note are the same. The endpoint callback function in IN direction is
USB_DeviceCdcAcmBulkIn() , and the callback function in OUT direction is USB_DeviceCdcAcmBulkOut() , that is, the functions
of the 15 VCOMs implementations are the same: transmits the data received from USB host to the USB host.
5.2 USB device request
The processing of standard requests and class requests is performed in the callback function of the control endpoint. The USB
host obtains the information of the USB device and performs related configuration on the USB device by sending a device request
NXP Semiconductors
Software workflow chart
USB to Multi VCOM on K32L2 Series MCU, Rev. 0, November 2019
Application Note 13 / 25