STM32F101xx, STM32F102xx, STM32F103xx, STM32F105xx and ...

RM0008
USB on-the-go full-speed (OTG_FS)
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
CTXPKT
FDMOD
FHMOD
Reserved
NPTXRWEN
TRDT
HNPCAP
SRPCAP
Reserved
TOCAL
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r/rw
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Bits 31:20 Reserved.
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 28:15 Reserved
Bit 14 NPTXRWEN: Reserved non-periodic TxFIFO rewind enable
In Host mode, this bit should be set when only one channel is enabled. When this bit is set, the
core automatically retries an OUT transaction in case of NAK or timeout, without interrupting
the application.
In Device mode, this bit should be set only when one non-periodic IN endpoint is enabled at
any point in time, as can happen in mass storage applications. When this bit is enabled, the
core can internally handle the timeout on non-periodic endpoints without application
intervention.
Note: Accessible in both Device and Host modes.
Doc ID 13902 Rev 9 727/995