Intel EP80579 Guide

Intel
®
EP80579 Integrated Processor Product Line—Power Management and Reset Interface
Intel
®
EP80579 Integrated Processor Product Line
Platform Design Guide May 2010
88 Order Number: 320068-005US
7.3 Power Management
7.3.1 Supported Power States
EP80579 can be switched to a very low power state during what looks like to the user
as “off”. The traditional PC power states typically supported by IA-32 core, IMCH and
IICH components are employed by the EP80579 for this goal.
7.3.1.1 System States
•S0: Full On
• S3: Suspend to RAM (STR).
Memory is placed into “Self Refresh” before the system enters S3. All power on
EP80579 is removed except for the system memory power (VCC18). During this
state, no accesses are allowed from any agent and all devices are disabled. Power
to the core logic may not be maintained during this state so the internal register
contents will not remain valid while in this state. A reset is required during resume
from S3.
• S5: Soft Off. All power lost. Total reboot needed.
7.3.1.2 Main Memory States
The main memory is power managed during normal operation and in low power states.
Main memory states are:
• Power up: CKE asserted. Active mode
• Precharge Power down: CKE de-asserted (not self-refresh) with all banks closed
• Active Power down: CKE de-asserted (not self-refresh) with at least one bank
active
• Self-Refresh: CKE de-asserted using device self-refresh
7.3.1.3 IA-32 core States
The EP80579 supports the AutoHALT, Stop Grant and Sleep states for optimal power
management. See Figure 51 for a visual representation of the IA-32 core low-power
states.
Table 15. Three Basic System Power States
Platform
Power State
Basic Description
PC equivalent
System
States
CPU
States
Memory
States
System
Clocks
On Everything up and running. S0 C0,C1,C2 Full on On
Suspend
All systems powered off other
than main memory and logic
required to wake the system
S3
Powered
off
Self
Refresh
Off
Soft Off (S5)
All systems powered off and the
OS does not save any context.
The system is in the “soft” off
state and requires a complete
boot when it wakes.
Powered off
S5
Powered
off
Powered
off
Off

Intel EP80579 Specifications

General

Brand	Intel
Model	EP80579
Category	Computer Hardware
Language	English