Asus P4P8X - Manual (Page 30)

1-20 Chapter 1: Product introduction
2. USB device wake-up (3-pin USBPW12, USBPW34, USBPW56, USBPW78)
Set these jumpers to +5V to wake up the computer from S1 sleep mode (CPU
stopped, DRAM refreshed, system running in low power mode) using the
connected USB devices. Set to +5VSB to wake up from S3 and S4 sleep
modes (no power to CPU, DRAM in slow refresh, power supply in reduced
power mode).
The USBPWR12 and USBPWR34 jumpers are for the rear USB ports. The
USBPWR56 and USBPWR78 jumper is for the internal USB header that you
can connect to the front USB ports.
1. The USB device wake-up feature requires a power supply that can provide
at least 500mA on the +5VSB lead when these jumpers are set to +5VSB.
Otherwise, the system would not power up.
2. The total current consumed must NOT exceed the power supply capability
(+5VSB) whether under normal condition or in sleep mode.
P4P8X
®
P4P8X USB Device Wake Up
3 2 2 1
+5V
(Default)
+5VSB
USBPW12
USBPW34
3 2 2 1
+5V
(Default)
+5VSB
USBPW56
USBPW78
3. Keyboard power (3-pin KBPWR)
This jumper allows you to enable or disable the keyboard wake-up feature. Set
this jumper to pins 2-3 (+5VSB) if you wish to wake up the computer when you
press a key on the keyboard (the default value is [Disabled]). This feature
requires an ATX power supply that can supply at least 1A on the +5VSB lead
and a corresponding setting in the BIOS. (see section 2.5.1 Power Up Control)
P4P8X
®
P4P8X Keyboard Power Setting
(Default)
+5V +5VSB
KBPWR
2 3 1 2