Usb Host - ST STM32F101 series Reference Manual

USB on-the-go full-speed (OTG_FS)
The peripheral core provides the following status checks and interrupt generation:
•
Transfer completed interrupt, indicating that data transfer was completed on both the
application (AHB) and USB sides
•
Setup stage has been done (control-out only)
•
Associated transmit FIFO is half or completely empty (in endpoints)
•
NAK acknowledge has been transmitted to the host (isochronous-in only)
•
IN token received when Tx-FIFO was empty (bulk-in/interrupt-in only)
•
Out token received when endpoint was not yet enabled
•
Babble error condition has been detected
•
Endpoint disable by application is effective
•
Endpoint NAK by application is effective (isochronous-in only)
•
More than 3 back-to-back setup packets were received (control-out only)
•
Timeout condition detected (control-in only)
•
Isochronous out packet has been dropped, without generating an interrupt
28.6

USB host

This section gives the functional description of the OTG_FS in the USB host mode. The
OTG_FS works as a USB host in the following circumstances:
•
OTG A-host
–
•
OTG B-host
–
•
A-device
–
•
Host only (see figure
–
Note: On-chip 5 V V
available on the application board, a basic power switch must be added externally to drive
the 5 V V
required for the OTG A-host, A-device and host-only configurations.
The V
BUS
operations while the charge pump overcurrent output can be input to any GPIO pin
configured to generate port interrupts. The overcurrent ISR must promptly disable the V
generation.
831/1128
OTG A-device default state when the A-side of the USB cable is plugged in
OTG B-device after HNP switching to the host role
If the ID line is present, functional and connected to the A-side of the USB cable,
and the HNP-capable bit is cleared in the Global USB Configuration register
(HNPCAP bit in OTG_FS_GUSBCFG). Integrated pull-down resistors are
automatically set on the DP/DM lines.
Figure 305: USB host-only
The force host mode bit in the global USB configuration register (FHMOD bit in
OTG_FS_GUSBCFG) forces the OTG_FS core to work as a USB host-only. In this
case, the ID line is ignored even if present on the USB connector. Integrated pull-
down resistors are automatically set on the DP/DM lines.
generation is not supported. For this reason, a charge pump or, if 5 V are
BUS
line. The external charge pump can be driven by any GPIO output. This is
BUS
input ensures that valid V
DocID13902 Rev 15
connection).
levels are supplied by the charge pump during USB
BUS
RM0008
BUS