Srp-Capable Host; Usb Host States; Figure 360. Usb Host-Only Connection - ST STM32F40 Series Reference Manual

RM0090
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

Figure 360. USB host-only connection

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
30.6.1

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) section.
30.6.2

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).
V valid
BUS
When HNP or SRP is enabled the VBUS sensing pin (PA9) pin should be connected to
V . The V
BUS
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
GPIO+IRQ
STM32F4xx
STM32F4xx
OSC_IN
OSC_OUT
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
input ensures that valid V
BUS
Doc ID 018909 Rev 4
levels are supplied by the charge pump during USB
BUS
sensing option. This is done by setting the
BUS
valid level (5 V).
V
EN
STMPS2141STR
GPIO
Current limited
Overcurrent power distribution
switch
P 9
PA11
PA12
power while the USB session is suspended.
BUS
using the chosen GPIO, it must also set the port
BUS
levels are supplied by the charge pump
BUS
USB on-the-go full-speed (OTG_FS)
BUS
DD
5 V Pwr
(1)
VBUS
V
powered device. A basic power
BUS
A-device session request
BUS
is considered
DM
DP
SS
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