Interfaces and Connectors
VL-EPIC-25 Reference Manual
40
Pushbutton Reset
Connector J19 includes an input for a pushbutton reset switch. Shorting J19 pin 40 to ground
causes the Iguana to reboot. This must be a mechanical switch or an open-collector or open-drain
active switch with less than a 0.5V low-level input when the current is 1 mA. There must be no
pull-up resistor on this signal.
This connector uses IEC 61000-4-2-rated TVS components to help protect against ESD damage.
A reset button is provided on the VL-CBR-5013 breakout board. Terminal block J8 on the
breakout board also provides a reset signal on pin 1 and ground on pin 2.
Power Button
Connector J19 includes an input for a power button. Shorting J19 pin 41 to ground causes the
board to enter an S5 power state (similar to the Windows Shutdown state). Shorting it again will
return the board to the S0 power state and reboot 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).
This connector uses IEC 61000-4-2-rated TVS components to help protect against ESD damage.
A power button is provided on the VL-CBR-5013 breakout board. Terminal block J8 also
provides a power button signal on pin 3 and ground on pin 2.
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 by the BIOS. The behavior can be changed using the Restore AC
Power Loss parameter on the Chipset > South Bridge menu of the BIOS setup screens.
S
UPPORTED
P
OWER
S
TATES
The Iguana supports the following power states:
S0 (G0): Working.
S1 (G1-S1): 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.
S3 (G1-S3): Commonly referred to as Standby, Sleep, or Suspend-to-RAM. RAM
remains powered.
S4 (G1-S4): 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.
S5 (G2): 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.
G3: Mechanical off (ATX supply switch turned off).
