ST STM32F446 Series Reference Manual page 1112

USB on-the-go full-speed/high-speed (OTG_FS/OTG_HS)
Bits 31:22 Reserved, must be kept at reset value.
Bit 21 CURMOD: Current mode of operation
Indicates the current mode (host or device).
0: Device mode
1: Host mode
Bit 20 OTGVER: OTG version
Selects the OTG revision.
0:OTG Version 1.3. OTG1.3 is obsolete for new product development.
1:OTG Version 2.0. In this version the core supports only data line pulsing for SRP.
Bit 19 BSVLD: B-session valid
Indicates the device mode transceiver status.
0: B-session is not valid.
1: B-session is valid.
In OTG mode, you can use this bit to determine if the device is connected or disconnected.
Note: Only accessible in device mode.
Bit 18 ASVLD: A-session valid
Indicates the host mode transceiver status.
0: A-session is not valid
1: A-session is valid
Note: Only accessible in host mode.
Bit 17 DBCT: Long/short debounce time
Indicates the debounce time of a detected connection.
0: Long debounce time, used for physical connections (100 ms + 2.5 µs)
1: Short debounce time, used for soft connections (2.5 µs)
Note: Only accessible in host mode.
Bit 16 CIDSTS: Connector ID status
Indicates the connector ID status on a connect event.
0: The OTG_FS/OTG_HS controller is in A-device mode
1: The OTG_FS/OTG_HS controller is in B-device mode
Note: Accessible in both device and host modes.
Bits 15:13 Reserved, must be kept at reset value.
Bit 12 EHEN: Embedded host enable
It is used to select between OTG A device state machine and embedded host state machine.
0: OTG A device state machine is selected
1: Embedded host state machine is selected
Bit 11 DHNPEN: Device HNP enabled
The application sets this bit when it successfully receives a SetFeature.SetHNPEnable
command from the connected USB host.
0: HNP is not enabled in the application
1: HNP is enabled in the application
Note: Only accessible in device mode.
1112/1328 RM0390 Rev 4
RM0390