Host-Mode Features; Peripheral-Mode Features; Split Rail For Usb - ST STM32F423 Reference Manual

RM0430
33.2.2

Host-mode features

The OTG_FS interface main features and requirements in host-mode are the following:
•
External charge pump for V
•
Up to 12 host channels (pipes): each channel is dynamically reconfigurable to allocate
any type of USB transfer.
•
Built-in hardware scheduler holding:
–
–
• Management of a shared Rx FIFO, a periodic Tx FIFO and a nonperiodic Tx FIFO for
efficient usage of the USB data RAM.
33.2.3

Peripheral-mode features

The OTG_FS interface main features in peripheral-mode are the following:
•
1 bidirectional control endpoint0
•
5 IN endpoints (EPs) configurable to support bulk, interrupt or isochronous transfers
•
5 OUT endpoints configurable to support bulk, interrupt or isochronous transfers
•
Management of a shared Rx FIFO and a Tx-OUT FIFO for efficient usage of the USB
data RAM
•
Management of up to 6 dedicated Tx-IN FIFOs (one for each active IN EP) to put less
load on the application
•
Support for the soft disconnect feature.
33.2.4

Split rail for USB

In some package options it is possible to work with a split rail V
restrictive voltage specification than the V
When this is the case, and assuming that V
for V
DDUSB
For host only applications:
•
No special precautions are necessary.
For VBUS powered USB2.0 peripheral device:
•
No special precautions are necessary. V
reflected directly in the presence of power supplies on the MCU.
All other cases (V
• Refer to the datasheet (Electrical Characteristics, and Appendix for application block
diagrams). A different range of the V
Up to 12 interrupt plus isochronous transfer requests in the periodic hardware
queue
Up to 12 control plus bulk transfer requests in the non-periodic hardware queue
, please take the following precautions.
detection is required):
BUS
USB on-the-go full-speed (OTG_FS)
voltage generation.
BUS
which can work at a lower range.
DD
is indeed below the minimum functional level
DD
detection is not needed, as V
BUS
supply will apply this case.
DD
RM0430 Rev 8
which has a more
DDUSB
state is
BUS
1133/1324
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