Asus A55BM-A/USB3 - Manual (Page 28)

1-20 Chapter 1: Product introduction
8. USB 2.0 connectors (10-1 pin USB34, USB56)
These connectors are for USB 2.0 ports. Connect the USB module cable to any of
these connectors, then install the module to a slot opening at the back of the system
chassis. These USB connectors comply with USB 2.0 specification that supports up to
480Mbps connection speed.
Never connect a 1394 cable to the USB connectors. Doing so will damage the
motherboard!
The USB 2.0 module is purchased separately.
9. Serial port connector (10-1 pin COM)
This connector is for a serial (COM) port. Connect the serial port module cable to this
connector, then install the module to a slot opening at the back of the system chassis.
The COM module is purchased separately.
A55BM-A/USB3
A55BM-A/USB3 Serial port connectors
PIN 1
COM
D
C
D
DX
T
D
N
G
ST
R
I
R
DX
R
RT
D
RS
D
ST
C
A55BM-A/USB3
A55BM-A/USB3 USB2.0 connectors
PIN 1
USB+5V USB_P5- USB_P5+ GND NC
USB+5V USB_P6- USB_P6+
GND
USB56 USB34
PIN 1
USB+5V USB_P3- USB_P3+ GND NC
USB+5V USB_P4- USB_P4+
GND