USB on-the-go full-speed (OTG_FS)
RM0090
1266/1731
DocID018909 Rev 11
OTG_FS USB configuration register (OTG_FS_GUSBCFG)
Address offset: 0x00C
Reset value: 0x0000 0A00
This register can be used to configure the core after power-on or a changing to host mode
or device mode. It contains USB and USB-PHY related configuration parameters. The
application must program this register before starting any transactions on either the AHB or
the USB. Do not make changes to this register after the initial programming.
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
CTXPK
T
FD
M
O
D
FH
M
O
D
Reserved
TRDT
HNPCAP
SRPCAP
Res.
PHYS
EL
Reserved
TOCAL
rw rw rw
rw
r/
rw
r/
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wo
rw
Bits 31:20 Reserved, must be kept at reset value.
Bit 31
CTXPKT:
Corrupt Tx packet
This bit is for debug purposes only. Never set this bit to 1.
Note: Accessible in both device and host modes.
Bit 30
FDMOD:
Force device mode
Writing a 1 to this bit forces the core to device mode irrespective of the OTG_FS_ID input
pin.
0: Normal mode
1: Force device mode
After setting the force bit, the application must wait at least 25 ms before the change takes
effect.
Note: Accessible in both device and host modes.
Bit 29
FHMOD:
Force host mode
Writing a 1 to this bit forces the core to host mode irrespective of the OTG_FS_ID input pin.
0: Normal mode
1: Force host mode
After setting the force bit, the application must wait at least 25 ms before the change takes
effect.
Note: Accessible in both device and host modes.
Bits 28:14 Reserved, must be kept at reset value.
Bits 13:10
TRDT:
USB turnaround time
These bits allows to set the turnaround time in PHY clocks. They must be configured
according to
, depending on the application AHB frequency. Higher
TRDT values allow stretching the USB response time to IN tokens in order to compensate for
longer AHB read access latency to the Data FIFO.
Note: Only accessible in device mode.
Bit 9
HNPCAP:
HNP-capable
The application uses this bit to control the OTG_FS controller’s HNP capabilities.
0: HNP capability is not enabled.
1: HNP capability is enabled.
Note: Accessible in both device and host modes.