82801FB Datasheet, PDF (172/786 Pages) Intel Corporation – Intel I/O Controller Hub 6 (ICH6) Family

Functional Description
5.14.11.7 Controlling Leakage and Power Consumption
During Low-Power States
To control leakage in the system, various signals tri-state or go low during some low-power states.
General principles:
• All signals going to powered down planes (either internally or externally) must be either
tri-stated or driven low.
• Signals with pull-up resistors should not be low during low-power states. This is to avoid the
power consumed in the pull-up resistor.
• Buses should be halted (and held) in a known state to avoid a floating input (perhaps to some
other device). Floating inputs can cause extra power consumption.
Based on the above principles, the following measures are taken:
• During S3 (STR), all signals attached to powered down planes are tri-stated or driven low.
5.14.12 Clock Generators
The clock generator is expected to provide the frequencies shown in Table 5-38.
Table 5-38. Intel^® ICH6 Clock Inputs
Clock Domain Frequency Source
Usage
SATA_CLK
DMI_CLK
PCICLK
CLK48
CLK14
ACZ_BIT_CLK
LAN_CLK
100 MHz
Differential
100 MHz
Differential
33 MHz
48.000 MHz
14.318 MHz
12.288 MHz
0.8 to
50 MHz
Main Clock
Generator
Main Clock
Generator
Main Clock
Generator
Main Clock
Generator
Main Clock
Generator
AC ’97
Codec
LAN
Connect
Used by SATA controller. Stopped in S3 ~ S5 based on
SLP_S3# assertion.
Used by DMI and PCI Express*. Stopped in S3 ~ S5 based on
SLP_S3# assertion.
Desktop: Free-running PCI Clock to ICH6. Stopped in S3 ~ S5
based on SLP_S3# assertion.
Mobile: Free-running (not affected by STP_PCI# PCI Clock to
ICH6. This is not the system PCI clock. This clock must keep
running in S0 while the system PCI clock may stop based on
CLKRUN# protocol. Stopped in S3 ~ S5 based on SLP_S3#
assertion.
Used by USB controllers and Intel High Definition Audio
controller. Stopped in S3 ~ S5 based on SLP_S3# assertion.
Used by ACPI timers. Stopped in S3 ~ S5 based on SLP_S3#
assertion.
AC-link. Control policy is determined by the clock source.
NOTE: Becomes clock output when Intel High Definition Audio
is enabled.
LAN Connect Interface. Control policy is determined by the
clock source.
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Intel^® I/O Controller Hub 6 (ICH6) Family Datasheet