Pin Definition

Motherboard Pin Denition

1-3

1 Headers

1. Clear RTC RAM (2-pin CLRTC)

This header allows you to clear the Real Time Clock (RTC) RAM in

CMOS. You can clear the CMOS memory of date, time, and system setup

parameters by erasing the CMOS RTC RAM data. The onboard button

cell battery powers the RAM data in CMOS, which include system setup

information such as system passwords.

To erase the RTC RAM:

1. Turn OFF the computer and unplug the power cord.

2. Use a metal object such as a screwdriver to short the two pins.

3. Plug the power cord and turn ON the computer.

4. Hold down the <Del> key during the boot process and enter BIOS setup to re-

enter data.

• Ifthestepsabovedonothelp,removetheonboardbatteryandshortthetwopins

again to clear the CMOS RTC RAM data. After clearing the CMOS, reinstall the

battery.

• YoudonotneedtocleartheRTCwhenthesystemhangsduetooverclocking.For

system failure due to overclocking, use the CPU Parameter Recall (C.P.R.) feature.

Shut down and reboot the system, then the BIOS automatically resets parameter

settings to default values.

2. RTC Battery header (2-pin BATT_CON)

This connector is for the lithium CMOS battery.

3. Chassis intrusion header (4-1 pin CHASSIS)

This header is for a chassis-mounted intrusion detection sensor or

switch. Connect one end of the chassis intrusion sensor or switch cable

to this connector. The chassis intrusion sensor or switch sends a high-

level signal to this connector when a chassis component is removed or

replaced. The signal is then generated as a chassis intrusion event.

By default, the pin labeled “Chassis Signal” and “Ground” are shorted

with a jumper cap. Remove the jumper caps only when you intend to use

the chassis intrusion detection feature.

CLRTC

+3V_BAT

GND

PIN 1

VBAT

GND

BATT_CON

+5VSB_MB

Chassis Signal

GND

CHASSIS

E11133_MB_pin_definition_v2.indd 3 2015/12/28 17:21:46