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Chapter 3
Power and Sleep States
The following information only applies to the ReadyBoard 800, if an ATX power supply is used to
provide power. If a non-ATX power supply is used, then the ReadyBoard 800 is only controlled by the
power On/Off switch on the power supply and the various sleep states are not available.
Power On Switch
The Power On switch turns the ReadyBoard 800 and its attached power supply to a fully On condition,
if you are using an ATX power supply. Normally, if the operating system (OS) supports sleep states,
the OS will turn Off the ReadyBoard and its power supply during the OS shut down process. If the OS
supports sleep states, the Power On button typically, will also transition the ReadyBoard and its power
supply between a fully Powered On state, various sleep states depending on the OS control setting, and
a fully Powered Off state. If the OS does not support sleep states, then the Power On button only turns
power On or Off to the ReadyBoard 800.
The sleep states are OS dependent and not available if your OS does not support power management
based on the ACPI standard. An OS supporting ACPI will allow the Power On button to be configured
through a user interface.
The Power-On Switch is provided externally by connecting a momentary switch between pins 1 and 2
on the Utility connector (J18). The power on signal occurs when ground is placed on pin-1 of J18.
Sleep States (ACPI)
The ReadyBoard 800 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
ReadyBoard, such as Windows 98/2000/ME/NT/XP. The term "sleep" state refers to a low latency
(reduced power consumption) state, which can be re-started (awakened) restoring full operation to the
ReadyBoard 800.
In these various sleep states, the ReadyBoard 800 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. However,
when the ReadyBoard 800 detects certain activity (i.e. mouse, keyboard, or certain types of LAN
activity), it returns to a fully operational state.
The ReadyBoard 800 supports at least four 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 ReadyBoard 800 must either be powered Off (S5), or in
a sleep state (S1 or S4), and then the Power On/Off switch is pressed for less than 4 seconds
(default).
♦
The ReadyBoard 800 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 placing, 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 ReadyBoard 800 appears to be off including the Power On LED.
♦
Normally, to enter this sleep state, the ReadyBoard 800 must be fully powered on (S0) and
the OS transitions the ReadyBoard into this standby state (S1) under user control.
♦
To exit this sleep state, typically the power button is used to wake up the ReadyBoard 800 to
restore full operation, including the Power On LED. Typically, pressing the power switch for
less than 4 seconds (default) will restore full operation.
ReadyBoard 800
Reference Manual
Hardware
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