Srp-Capable Host; Usb Host States; Figure 352. Usb Host-Only Connection - ST STM32F207 Series Reference Manual

USB on-the-go full-speed (OTG_FS)
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.
The V
BUS
NOVBUSSENS bit in the OTG_FS_GCCFG register. In this case the V
internally to be always at V
1. STMPS2141STR needed only if the application has to support a V
switch can be used if 5 V are available on the application board.
2. V range is between 2 V and 3.6 V.
DD
29.6.1

SRP-capable host

SRP support is available through the SRP capable bit in the global USB configuration
register (SRPCAP bit in OTG_FS_GUSBCFG). With the SRP feature enabled, the host can
save power by switching off the V
The SRP host mode program model is described in detail in the
protocol
29.6.2

USB host states

Host port power
On-chip 5 V V
available on the application board, a basic power switch, must be added externally to drive
the 5 V V
application decides to power on V
power bit in the host port control and status register (PPWR bit in OTG_FS_HPRT).
968/1381
line. The external charge pump can be driven by any GPIO output. This is
BUS
input ensures that valid V
pin can be freed by disabling the V
BUS

Figure 352. USB host-only connection

GPIO + IRQ
OSC_IN
OSC_OUT
section.
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. When the
BUS
levels are supplied by the charge pump during USB
BUS
sensing option. This is done by setting the
BUS
valid level (5 V).
V
DD
5 V
EN
STMPS2141STR
GPIO
Current-limited
power distribution
Overcurrent
switch
power while the USB session is suspended.
BUS
using the chosen GPIO, it must also set the port
BUS
RM0033 Rev 9
is considered
BUS
5 V Pwr
(2)
VBUS
DM
DP
V
SS
powered device. A basic power
BUS
A-device session request
RM0033
BUS
MSv36915V2