
EPM-31 Hardware Reference Manual
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Multi-purpose I/O
USB Interfaces
The EPM-31 includes four USB 2.0 host ports and one USB 3.0 host port. The four USB 2.0
ports are incorporated into the J4 user I/O connector, with standard USB Type A connectors
located on the VL-CBR-4005B paddleboard. Connector J16 on the bottom side of the board
provides a USB 3.0 Micro-A (host) connector. Figure 15 shows the location of the USB 3.0 port.
This interface can operate using either the Atom processor’s EHCI controller or its xHCI
controller. To use the USB 3.0 Super Speed mode, the xHCI controller must be used. USB
controller selection is set in the BIOS. By default, EHCI is used. Some older operating systems
(such as MS-DOS) may not support xHCI.
Figure 15. Location of the USB 3.0 Port (Bottom Side of the Board)
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