stm32 /stm32u5 /STM32U5A9 /OTG_HS /GRXSTSP_DEVICE

This description is for register GRXSTSP in Device mode. Similarly to GRXSTSR (receive status debug read register) where a read returns the contents of the top of the receive FIFO, a read to GRXSTSP (receive status read and pop register) additionally pops the top data entry out of the Rx FIFO. The core ignores the receive status pop/read when the receive FIFO is empty and returns a value of 0x00000000. The application must only pop the receive status FIFO when the receive FIFO non-empty bit of the core interrupt register (RXFLVL bit in GINTSTS) is asserted.