RM0008 USB on-the-go full-speed (OTG_FS)
Doc ID 13902 Rev 12 893/1096
This section explains the initialization of the OTG_FS controller after power-on. The
application must follow the initialization sequence irrespective of host or device mode
operation. All core global registers are initialized according to the core’s configuration:
1. Program the following fields in the OTG_FS_GAHBCFG register:
– Global interrupt mask bit GINTMSK = 1
– RxFIFO non-empty (RXFLVL bit in OTG_FS_GINTSTS)
– Periodic TxFIFO empty level
2. Program the following fields in the OTG_FS_GUSBCFG register:
– HNP capable bit
– SRP capable bit
– FS timeout calibration field
– USB turnaround time field
3. The software must unmask the following bits in the OTG_FS_GINTMSK register:
OTG interrupt mask
Mode mismatch interrupt mask
4. The software can read the CMOD bit in OTG_FS_GINTSTS to determine whether the
OTG_FS controller is operating in host or device mode.