4 universal serial bus (usb), 1 signal description, Niversal – IEI Integration ICE-DB-T6 User Manual

Page 46: Erial, Usb)

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Type 6 Carrier Board Design Guide

Page 36

3.4 Universal Serial Bus (USB)

The Universal Serial Bus (USB) provides a bi-directional, isochronous, hot-attachable

Plug and Play serial interface for external peripheral devices. A COM Express Module

provides a minimum of four USB ports and can support up to eight USB 2.0 ports and four

USB 3.0 ports.

The USB physical topology consists of connecting the downstream hub port to the

upstream port of another hub or to a device. The USB can operate at three speeds.

High-speed (480 Mb/s) and full-speed (12 Mb/s) require the use of a shielded cable with

two power conductors and twisted pair signal conductors. Low-speed (1.5 Mb/s) does not

require the use of a cable with twisted pair signal conductors, but it is recommended to do

so.

3.4.1 Signal Description

Table 3-7 shows COM Express USB signals, including pin number, signals, I/O, power

plane, terminal resistors, damping resistors and descriptions.

Pin

Signal

I/O

Description

A46
A45

USB0+
USB0-

I/O

USB Differential Data Port 0.

B46
B45

USB1+
USB1-

I/O

USB Differential Data Port 1.

A43
A42

USB2+
USB2-

I/O

USB Differential Data Port 2.

B43
B42

USB3+
USB3-

I/O

USB Differential Data Port 3.

A40
A39

USB4+
USB4-

I/O

USB Differential Data Port 4.

B40
B39

USB5+
USB5-

I/O

USB Differential Data Port 5.

A37
A36

USB6+
USB6-

I/O

USB Differential Data Port 6.

B37
B36

USB7+
USB7-

I/O

USB Differential Data Port 7.

B44 USB_0_1_OC# I 3.3V CMOS

USB over-current sense, USB ports 0 and 1. A pull-up for this
line shall be present on the module. An open drain driver from
a USB current monitor on the Carrier Board may drive this
line low. Do not pull this line high on the Carrier Board.

A44 USB_2_3_OC# I 3.3V CMOS

USB over-current sense, USB ports 2 and3. A pull-up for this
line shall be present on the module. An open drain driver from

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