Power Button; Supported Power States; Table 9: Supported Power States - VersaLogic VL-EBX-38 Hardware Reference Manual

P B
OWER UTTON
User I/O connector J4 includes an input for a push-button power switch. Shorting J4, pin 17 to
ground causes the board to enter an S5 power state (similar to the Windows Shutdown state).
Shorting it again returns the board to the S0 power state and reboots the board. The button can be
configured in Windows to enter an S3 power state (Sleep, Standby, or Suspend-to-RAM), an S4
power state (Hibernate or Suspend-to-Disk), or an S5 power state (Shutdown or Soft-Off).
The input can be connected to ground using the normally open contacts of a pushbutton switch or
a relay, or with a switching transistor (open-collector or open-drain) capable of sinking 3.3 mA
with a voltage drop that is less than 500 mV (there is a 1 kΩ resistor on the EBX-38 pulled up to
3.3 V). Do not add an external pull-up resistor to this signal.
A power button is provided on the CBR-4005B paddleboard. See Figure 24 on page 52 for the
location of the power button on the CBR-4005B paddleboard.
In configurations where a power button is not connected to the board, if the system is put into an
S5 state, power can be restored by turning off the power supply and turning it back on. This
behavior is set by default in the BIOS.
S P
UPPORTED OWER
This table lists the board's supported power states.

Table 9: Supported Power States

Power State
S0 (G0)
S1 (G1-S1)
S3 (G1-S3)
S4 (G1-S4)
S5 (G2)
G3
EBX-38 Hardware Reference Manual
S
TATES
Working
All processor caches are flushed, and the CPUs stop executing instructions. Power to
the CPUs and RAM is maintained. Devices that do not indicate they must remain on
may be powered down.
Commonly referred to as Standby, Sleep, or Suspend-to-RAM. RAM remains powered.
Hibernation or Suspend-to-Disk. All content of main memory is saved to non-volatile
memory, such as a hard drive, and is powered down.
Soft Off. Almost the same as G3 Mechanical Off, except that the power supply still
provides power, at a minimum, to the power button to allow return to S0. A full reboot is
required. No previous content is retained. Other components may remain powered so
the computer can "wake" on input from the keyboard, clock, modem, LAN, or USB
device.
Mechanical off (ATX supply switch turned off).
Description
Board Features
18