BIOS SPECIFICATION
6-15
Table 5-2. KBC GPIO Definition
Port I/O
Type Input Pin
Pull-up/down Name Output Pin
Default Value Description
A.0 O BRIGHT_PWM Low Used to adjust LCD backlight
A.1 NC
A.2 O BAT1_CNT1# High BAT1_CNT1# signal to battery
A.3 NC
A.4 O CHG_LED_UP# High When battery is charging, charging LED will
be turned on by this pin
A.5 O PWR_LED_UP# High When system is powered on, power LED will
be turned on by this pin
A.6 O BATSEL_3S# Low BATSEL_3S# signal to battery charging
circuit
A.7 O LCD_BACKOFF# Low For LCD back light control
B.0 O NUM_LED Low Number Lock Indicator
B.1 O CAP_LED Low CAP L ock Indicator
B.2 O SCRL_LED Low Scroll Lock Indicator
B.3 A SMCLK_BAT SMBUS clock pin (to battery)
B.4 A SMDATA_BAT SMBUS data pin (to battery)
B.5 O A20GATE Low A20 is gated by this pin from KBC
B.6 O RCIN# Low System reset signal from KBC
B.7 O THRO_CPU Low This pin is used for CPU throttling. To set it
high to enable CPU throttling. To set it low to
disable CPU throttling.
C.0 NC
C.1 A SMB1_CLK SMBUS1 clock pin (to thermal sensor)
C.2 A SMB1_DAT SMBUS1 data pin (to thermal sensor)
C.3 O EMAIL_LED# High Email incoming Indicator
C.4 A ACIN_OC# For AC adapter in/out detection
C.5 O OP_SD# Low EC MUTE on/off switch pin
C.6 A BAT_IN_OC# For battery in/out detection
C.7 NC
D.0 I PM_SUSB# PM_SUSB signal from ICH7-M
D.1 I PM_SUSC# PM_SUSC signal from ICH7-M
D.2 A PLT_RST# Platform reset signal from ICH7-M
D.3 O KB_SCI# HIGH SCI pin to notify system at runtime or wake
up events from KBC
D.4 NC
D.5 NC
D.6 A FAN0_TACH FAN0 tachometer
D.7 NC
E.0 I Pull-Up EMAIL# For Email instant key
E.1 I Pull-Up INTERNET# For Internet instant key
E.2 I Pull-Up MARATHON# For Marathon instant key
E.3 I Pull-Up DISTP# For Padlock instant key
E.4 A PWRSW#_EC For Power Button
E.5 NC
E.6 I LID_EC# For LID Event
E.7 NC
F.0 O EXT_PS2_CLK Low External PS2 clock pin
F.1 O EXT_PS2_DAT Low External PS2 data pin
F.2 NC
F.3 NC
F.4 A TPAD_CLK Touch Pad clock pin
F.5 A TPAD_DAT Touch Pad data pin
F.6 I Pull-Up PWRLMT# For Power Limit function
F.7 NC