STM32F101xx, STM32F102xx, STM32F103xx, STM32F105xx and ...

USB on-the-go full-speed (OTG_FS)
RM0008
OTG_FS device control IN endpoint 0 control register (OTG_FS_DIEPCTL0)
Address offset: 0x900
Reset value: 0x0000 0000
This section describes the device control IN endpoint 0 control register. Nonzero control
endpoints use registers for endpoints 1–15.
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
EPENA
EPDIS
Reserved
SNAK
CNAK
TXFNUM
STALL
Reserved
EPTYP
NAKSTS
Reserved
USBAEP
MPSIZ
Reserved
rs r w w rw rw rw rw rs r r r r rw rw
Bit 31 EPENA: Endpoint enable
The application sets this bit to start transmitting data on the endpoint 0.
The core clears this bit before setting any of the following interrupts on this endpoint:
– Endpoint disabled
– Transfer completed
Bit 30 EPDIS: Endpoint disable
The application sets this bit to stop transmitting data on an endpoint, even before the transfer
for that endpoint is complete. The application must wait for the Endpoint disabled interrupt
before treating the endpoint as disabled. The core clears this bit before setting the Endpoint
disabled interrupt. The application must set this bit only if Endpoint enable is already set for
this endpoint.
Bits 29:28 Reserved
Bit 27 SNAK: Set NAK
A write to this bit sets the NAK bit for the endpoint.
Using this bit, the application can control the transmission of NAK handshakes on an endpoint.
The core can also set this bit for an endpoint after a SETUP packet is received on that
endpoint.
Bit 26 CNAK: Clear NAK
A write to this bit clears the NAK bit for the endpoint.
Bits 25:22 TXFNUM: TxFIFO number
This value is set to the FIFO number that is assigned to IN endpoint 0.
Bit 21 STALL: STALL handshake
The application can only set this bit, and the core clears it when a SETUP token is received for
this endpoint. If a NAK bit, a Global IN NAK or Global OUT NAK is set along with this bit, the
STALL bit takes priority.
Bit 20 Reserved
Bits 19:18 EPTYP: Endpoint type
Hardcoded to ‘00’ for control.
762/995 Doc ID 13902 Rev 9