ST STM32F40 Series User Manual

USB on-the-go full-speed (OTG_FS) RM0090
1091/1422 Doc ID 018909 Rev 4
OTG_FS device control IN endpoint 0 control register (OTG_FS_DIEPCTL0)
Address offset: 0x900
Reset value: 0x0000 0000
This section describes the OTG_FS_DIEPCTL0 register. Nonzero control endpoints use
registers for endpoints 1–3.
313029282726252423222120191817161514131211109876543210
EPENA
EPDIS
Reserved
SNAK
CNAK
TXFNUM
STALL
Reserved
EPTYP
NAKSTS
Reserved
USBAEP
Reserved
MPSIZ
r 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, must be kept at reset value.
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, must be kept at reset value.
Bits 19:18 EPTYP: Endpoint type
Hardcoded to ‘00’ for control.

ST STM32F40 Series Specifications

General

Brand	ST
Model	STM32F40 Series
Category	Microcontrollers
Language	English