SYSTEM INTERFACE SIGNALS
Signal groupSignalPinsDirectionDescription
Power+3.3 V
+3.3 V
+1.5 V
GND		2
1
3
12		 Primary 3.3-V source
Auxiliary 3.3-V source
Primary 1.5-V source
System ground
 
100-MHz clock
PCI ExpressPET
PER
REFCLK		2
2
2		out
in
in		PCI Express 1x lane
Universal
Serial Bus		USB_D2in/outUSB 2.0 interface
Auxiliary
(3.3 V compliant)		PERST#
CLKREQ#
WAKE#		1
1
1		in
out
out		Functional reset
Reference clock req.
Wakeup event
SMBusSMB_DATA
SMB_CLK		1
1		in/out
in		SMBUS 2.0 interface
Comm. specificLED_WPAN#
LED_WLAN#
LED_WWAN#		1
1
1		out
out
out		Status LED indicators
ReservedUndefined18 For future use