ST STM32F446 Series Reference Manual page 1209

RM0390
1. Initialize channel 1
2. Write the first packet for channel 1
3. Along with the last word write, the core writes an entry to the non-periodic request
queue
4. As soon as the non-periodic queue becomes non-empty, the core attempts to send an
OUT token in the current frame
5. Write the second (last) packet for channel 1
6. The core generates the XFRC interrupt as soon as the last transaction is completed
successfully
7. In response to the XFRC interrupt, de-allocate the channel for other transfers
8. Handling non-ACK responses
USB on-the-go full-speed/high-speed (OTG_FS/OTG_HS)
RM0390 Rev 4 1209/1328
1264