Kontron SMARC-sA3874i - Manual (Page 26)

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User’s Guide
3.2.12 USB Interfaces
The Kontron sA3874i module supports two USB ports (USB 0:1). Per the ULP-COM specification, the Kontron
sA3874i USB0 port is capable of functioning either as a client or host device. The sA3874i module also supports
one additional USB2.0 host port, on ULP-COM USB1. This product does not implement the optional third USB
interface defined in the ULP-COM spec.
USB interface signals are exposed on the ULP-COM sA3874i edge connector as shown below:
ULP-COM sA3874i Edge finger TI Cortex A8 CPU Net Name Notes
Pin # Pin Name Pin # Pin Name
USB0 Port
P60 USB0_P AG11 USB0_DP USB0+
USB0 port data
pair
P61 USB0_N AH11 USB0_DM USB0-
P63 USB0_VBUS_DET AG12 USB0_VBUSIN USB0_VBUS_DET
USB host power
detection, when
this port is used
as a device.
P64 USB0_OTG_ID AG10 USB0_ID USB0_OTG_ID
USB OTG ID
input, active
high
USB1 Port
P65 USB1_P AG13 USB1_DP USB1+
USB1 port data
pair
P66 USB1_N AH13 USB1_DM USB1-
The ULP-COM Hardware specification defines USBx_EN_OC# (where x is 0 and 1 for use with USB0 and USB1) pins
as multifunction pins to use for power enable of USBx ports, as well as for over current indication. The ULP-COM
sA3874i complies with this definition. These nets are provided with pull up resistors on the Module. The Module
CPLD contains the glue logic required for this implementation.
The sA3874i Module USB power-enable and over-current indication logic implementation is shown in the following
block diagram. There are 10K pull-up resistors on the Module on the ULP-COM USBx_EN_OC# lines. The CPLD
outputs driving the USBx_EN_OC# lines are open-drain. The Carrier board USB power switch, if present, is enabled
by virtue of the 10K Module pull-up to 3.3V.