ACPI features include:
•Plug and Play (including bus and device enumeration)
•Power management control of individual devices,
•Methods for achieving less than
•A
•Support for multiple
•Support for a front panel power and sleep mode switch
The Server Board
•S0: Normal running state.
•S1: Processor sleep state. No context will be lost in this state and the processor caches will maintain coherency.
•S3: Suspend to RAM (Instantly Available PC Technology).
•S4: Hibernate or Save to Disk. The memory and machine state are saved to disk. Pressing the power button or another
•S5: Soft off. Only the RTC section of the chipset is running in this state.
CAUTION
The system is off only when the AC power is disconnected.
Table 8 lists the system states based on how long the power switch is pressed, depending on how ACPI is configured with an
Table 8. Effects of Pressing the Power Switch under ACPI
| …and the power switch is |
|
If the system is in this state… | pressed for | …the system enters this state |
|
|
|
Off | Less than four seconds | |
(ACPI S5 – Soft off) |
| (ACPI S0 – working state) |
|
| |
|
|
|
On | Less than four seconds | |
(ACPI S0 – working state) |
| (ACPI S1 – sleeping state) |
|
| |
|
|
|
On | More than four seconds | Fail safe |
(ACPI S0 – working state) |
| (ACPI S5 – Soft off) |
|
| |
|
|
|
Sleep | Less than four seconds | |
(ACPI S1 – sleeping state) |
| (ACPI S0 – working state) |
|
| |
|
|
|
Sleep | More than four seconds | |
(ACPI S1 – sleeping state) |
| (ACPI S5 – Soft off) |
|
| |
|
|
|
Server Board Features | 25 |