Signals Requiring Carrier Board Termination; Ethernet; Usb - Kontron ETXexpress-WPM User Manual

Signals Requiring Carrier Board Termination

Some signals, detailed below, require Carrier Board termination for proper operation. If
the signals and the feature are not used, no Carrier Board termination is required, and
the pins may be left open.

Ethernet

External Ethernet magnetics shall be implemented on the Carrier Board.

USB

No termination is required on USB pairs. A common mode choke is advisable if USB
pairs on the Carrier Board are routed to a connector for use with an external cable.
Signals USB_0_1_OC#, USB_2_3_OC#, USB_4_5_OC# and USB_6_7_OC# are used
to flag a USB over-current situation. Carrier Board USB current monitors may pull these
lines to GND with open drain drivers to indicate that the monitor's current limit has been
exceeded. Do not pull up these lines to 3.3V on the Carrier Board – this shall be done
on the module.
page 82 ETXexpress-WPM User's Guide