UM1585
USB 2.0 subsystem
Doc ID 023872 Rev 1
5 USB
2.0
subsystem
5.1 Host
ports
The board has two host ports that are fully compliant with the USB 2.0 specification (two
controllers with one port each). This means that the two hosts can work in concurrent mode
with the maximum possible bandwidth. Each host has also full control of the VBUS supplied
by the ST2052 or STMP2252MTR power switch that also provides over current protection in
case of a short circuit in the USB cable. The ports are equipped with LEDs showing the
power status of each port (the green LED indicates the presence of VBUS and the red one
the current limiter status).
5.2 Host
LEDs
USB host LEDs
5.3 OTG
USB
One OTG micro USB-AB connector is present on the board.
5.3.1
SPEAr USB interface power
SPEAr USB phy (2.5 V) could be powered by an internal regulator or use external power.
Table 11.
USB host LEDs
Reference Description
D7
Red
USB HOST1 OVERCURRENT
: Abnormal current flowing on USB HOST 1 port
D8
Green
USB HOST1 VBUS
: VBUS present on USB HOST port 1
D9
Green
USB HOST1 VBUS
: VBUS present on USB HOST port 2
D10
Red
USB HOST2 OVERCURRENT
: Abnormal current flowing on USB HOST 2 port
Table 12.
OTG micro USB-AB LEDs
Reference Description
D20 Red
USB OTG OVERCURRENT
: Abnormal current flowing on OTG USB
D19 Green
USB OTG VBUS
: VBUS present on OTG USB