AT32WB415
Series Reference Manual
2022.04.13
Page 291
Ver 2.00
The OTGFS supports SOF pulse feature: a SOF pulse generates at a SOF packet, the pulse can output
to the timer 2;
Suspend mode is supported. The OTGFS goes into power-saving mode after Suspend mode is entered.
As a device, a unified FIFO buffer is allocated for all OUT endpoints, and a separate FIFO buffer is
provided to each of IN endpoints. As a host, a unified receive FIFO is allocated for all receive channels,
a unfied transmit FIFO for all non-periodic transmit channels, and a unified transmit FIFO for all periodic
transmit channels.
OTGFS supports suspend mode, and goes into low-power mode after entering suspend mode. Besides,
power consumption reduction can be achieved through the PWRDOWN bit in the OTGS_GCCFG or the
STOPPCLK bit in the OTGFS_PCFCCTL register.
20.3 OTGFS clock and pin configuration
20.3.1 OTGFS clock configuration
The OTGFS interface has two clocks: USB control clock and APB bus clock. The USB full-speed device
bus speed standard is 12Mb/s
±
0.25%, so it is necessary to supply 48MHz
±
0.25% for the OTGFS to
perform USB bus sampling.
OTGFS 48M clock source:
Divided by PLL
The PLL output frequency must ensure that the USBDIV (see CRM_CFG register) can be divided
to 48MHz.
Note: The APB clock frequency must be greater than 30 MHz when OTGFS is enabled.
20.3.2 OTGFS pin configuration
The OTGFS input/output pins are multiplexed with GPIOs. The GPIOs are used as OTGFS in one of
the following conditions:
Table 20-1 OTGFS input/output pins
Pin
GPIO
Description
OTGFS_D-
PA11
Enable OTG in CRM, and PWRDOWN=1
PA12
Enable OTG in CRM, and PWRDOWN=1
20.4 OTGFS interrupts
shows the OTGFS interrupt hierarchy. Refer to the OTGFS interrupt register
(OTGFS_GINTSTS) and OTGFS interrupt mask register (OTGFS_GINTMSK).