AT32F425
Series Reference Manual
2022.03.30
Page 408
Ver 2.01
A write to this bit clears the NAK bit for the endpoint.
Bit 25: 22 TXFNUM
0x0
rw
TxFIFO number
The endpoint 0 can only use FIFO0.
Bit 21
STALL
0x0
rw1s
STALL handshake
The application sets this bit, and the controller clears this
bit when a SETUP token is received. If a NAK bit, a global
non-periodic IN NAK or global OUT NAK bit is set along
with this bit, the STALL bit has priority.
Bit 20
Reserved
0x0
resd
Kept at its default value.
Bit 19: 18 EPTYPE
0x0
ro
Endpoint type
Set to 0 by hardware for control endpoints.
Bit 17
NAKSTS
0x0
ro
NAK status
Indicates the following:
0: The controller is transmitting non-NAK handshakes
based on the FIFO status
1: The controller is transmitting NAK handshakes on this
endpoint
When this bit is set, either by the application or controller,
the controller stops transmitting data, even if there are
space available in the receive FIFO. The controller always
responds to SETUP data packets with an ACK handshake,
irrespective of this bit’s setting.
Bit 16
Reserved
0x0
resd
Kept at its default value.
Bit 15
USBACEPT
0x0
ro
USB active endpoint
This bit is always set to 1, indicating that the control
endpoin 0 is always active in all configurations and
interfaces.
Bit 14: 2
Reserved
0x0000
resd
Kept at its default value.
Bit 1: 0
MPS
0x0
rw
Applies to IN and OUT endpoints
The application uses this bit to program the maximum
packet size for the current logical endpoint.
00: 64 bytes
01: 32 bytes
10: 16 bytes
11: 8 bytes
20.6.5.10
OTGFS device IN endpoint-x control register
(OTGFS_DIEPCTLx) (x=x=1
…
7, where x is endpoing number)
The application uses this register to control the behavior of the endpoints other than endpoint 0.
Bit
Register
Reset value
Type
Description
Bit 31
EPTENA
0x0
rw1s
Endpoint enable
The application sets this bit to start transmitting data on an
endpoint. The controller clears this bit before the
generation one of the following interrupts on this endpoing:
–
SETUP stage done
–
Endpoint disabled
–
Transfer completed
Bit 30
EPTDIS
0x0
rw1s
Endpoint disable
The application sets this bit to stop transmitting data on an
endpoint, even if the transfer on that endpint is incomplete.
The application must wait for the endpoint disabled
interrupt before treating the endpoint as disabled. The
controller clears this bit before setting the endpoint
disabled interrupt. The application must set this bit only
when the endpoint enabled set.
Bit 29
SETD1PID/
SETODDFR
0x0
wo
Set DATA1 PID
Applies to interrupt/bulk IN endpoints only. Writing to this
bit sets the endpoint data PID bit in this register to DATA1.
Set odd frame
Applies to synchronous IN endpoints only. Writing to this
bit sets the Even/Odd frame to odd frame.
0: Disabled Set DATA1 PID disabled or Do not force odd