FIC A360 - Manual (Page 79)

Software Functional Overview
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FIC A360 Service Manual
is lost (CPU or chip set) and hardware maintains all system context.
S2 Sleeping State
The S2 sleeping state is a low wake-up latency sleeping state. This state is similar to the S1
sleeping state except the CPU and system cache context is lost (the OS is responsible for
maintaining the caches and CPU context). Control starts from the processor’s reset vector
after the wake-up event.
S3 Sleeping State (STR mode)
The S3 sleeping state is a low wake-up latency sleeping state where all system context is lost
except system memory. CPU, cache, and chip set context are lost in this state. Hardware
maintains memory context and restores some CPU and L2 configuration context. Control
starts from the processor’s reset vector after the wake-up event.
S4 Sleeping State (STD mode)
The S4 sleeping state is the lowest power, longest wake-up latency sleeping state supported
by ACPI. In order to reduce power to a minimum, it is assumed that the hardware platform
has powered off all devices. Platform context is saved in disk.
S5 Soft Off State
The S5 state is similar to the S4 state except the OS does not save any context nor enable any
devices to wake the system. The system is in the “SOFF” off state and requires a complete
boot when awakened. Software uses a different state value to distinguish between the S5
state and the S4 state. This is to allow for initial boot operations within the BIOS to
distinguish whether or not the boot is going to wake from a saved memory image.