STM32F101xx, STM32F102xx, STM32F103xx, STM32F105xx and ...

USB on-the-go full-speed (OTG_FS)
RM0008
entries) = 512 bytes of USB bulk traffic can be scheduled by the application and
autonomously executed by the host at the maximum full-speed data rate without any
application intervention.
● To post an out periodic (nonperiodic) transaction request to the host scheduler the
application has to:
– configure the transfer parameters on an available host channel
– enable the configured channel
– check that there is at least 1 entry available in the periodic (nonperiodic) request
queue by reading the HPTXSTS bit in the OTG_FS_GNPTXSTS register
– check that there is enough FIFO space in the periodic (nonperiodic) Tx FIFO (see
Section 26.11.2: Host Tx FIFOs) by reading the HPTXSTS (GNPTXSTS) register.
This step may not be necessary if the application submits the host transaction
request upon reception of the periodic (nonperiodic) Tx FIFO half or completely
empty interrupt
– push the data payload to the associated FIFO address (push register). There is
one push register for each enabled host channel. The data payload is
automatically redirected to the periodic or nonperiodic Tx FIFO according to the
host channel EPTYP bitfield in the OTG_FS_HCCHARx register. When the last
32-bit word data are written to the FIFO, an active entry is inserted at the bottom of
the periodic (nonperiodic) request queue and the transaction request is scheduled
for execution
● To post an IN periodic (nonperiodic) transaction request to the host scheduler the
application has to:
– configure the transfer parameters on an available host channel
– enable the configured channel with the channel enable bit in the host channel
characteristics register (CHENA bit in OTG_FS_HCCHARx). This inserts an active
entry at the bottom of the periodic (nonperiodic) request queue and the
transaction request is scheduled for execution
26.7 SOF trigger
Figure 264. SOF connectivity
STM32F105xx
STM32F107xx
PA8
SOF pulse output, to
external audio control
TIM2
ITR1
SOF
pulse
SOFgen
PA9
PA11
PA12
PA10
VBUS
D -
D +
ID
V SS
USB micro-AB connector
ai17120
708/995 Doc ID 13902 Rev 9