Ampro Corporation XTX 820 manual Sleep States Acpi

Chapter 3 Hardware

Typically, an OS that supports ACPI, also allows the Power-On switch to be configured through a user interface. The Power-On switch for the XTX 820 must be provided on, or connected to the baseboard.

Sleep States (ACPI)

The XTX 820 supports the ACPI (Advanced Configuration and Power Interface) standard, which is a key component of certain Operating Systems’ (OS’s) power management. The supported features (sleep states) listed here are only available when an ACPI-compliant OS is used for the XTX 820, such as Windows 2000/XP. The term “sleep state" refers to a low wake latency (reduced power consumption) state, which can be re-started (awakened) restoring full operation to the XTX 820.

In these various sleep states, the computer appears to be off, indicated by such things as no display on the attached monitor and no activity for the connected CD-ROM or hard drives. Normally, when a computer detects certain activity (i.e. power switch, mouse, keyboard, serial port, or certain types of LAN activity), it returns to a fully operational state.

NOTE	Currently, the Power-On switch, SMBus Alert, Wake-on-Ring, Wake-on-
	LAN, Wake on PME, and Keyboard/Mouse activity are the only activities
	that will wake the XTX 820 from a powered down state (soft off), such as
	Standby (S1), Suspend-to-RAM (S3), Hibernate (S4) and Power Off (S5).
	However, not all of the listed activities (called "wake events") will wake
	each sleep state. Refer to Wake Up Activities and the XTX 820 Software
	and Hardware Release Notes for more information.

The XTX 820 supports at least five ACPI power states, depending on the operating system used and its ability to manage sleep states. Typically, the Power-On switch is used to wake up from a sleep state, or transition from one state to another, but this is dependent on the operating system.

•1st state is normal Power On (S0).

♦To go to a fully powered on state, the XTX 820 must either be powered Off (S5), or in a sleep state (S1 or S4), and then the Power-On switch is pressed for less than 4 seconds (default).

♦The XTX 820 can transition from this state (S0) to the various states described below, depending on the power management capability of the OS and how it is programmed.

•2nd state is a standby state (S1).

In this state there are no internal operations taking place, except for the internal RTC (real time clock) and the contents of RAM. This includes no activity for the CPU, CD-ROM, or hard disk drives. The XTX 820 appears to be off including any power-on LED indicators.

♦Normally, to enter this sleep state, the XTX 820 must be fully powered on (S0) and the OS transitions the XTX 820 into this standby state (S1) under user control.

♦To exit this sleep state a wake up event, such as the Power-On switch, is used to wake up the XTX 820 and restore full operation, including any power LED indicators. Typically, pressing the Power-On switch for less than 4 seconds (default) will restore full operation.

•3rd state is a suspend-to-RAM state (S3).

In this state there are no internal operations taking place, except for the internal RTC (real time clock) and the contents of RAM. This includes no activity for the CPU, CD-ROM, or hard disk drives. The XTX 820 appears to be off including any power LED indicators.

♦Normally, to enter this sleep state, the XTX 820 must be fully powered on (S0) and the OS transitions the XTX 820 into this suspend-to-RAM (S3) state under user control.

♦To exit this sleep state a wake up event, such as the Power-On switch, is used to wake up the XTX 820 and restore full operation, including any power LED indicators. Typically, pressing the Power-On switch for less than 4 seconds (default) will restore full operation.

XTX 820 Reference Manual 59