307013-003 Datasheet, PDF (249/848 Pages) Intel Corporation – Intel I/O Controller Hub 7

Functional Description
5.25.5.2
5.25.5.3
Note:
5.26
5.26.1
5.26.2
SMI# Based Global Write Protection
The ICH7 provides a method for blocking writes to the SPI flash when the Write Protect
bit is cleared (i.e., protected). This is achieved by checking the Opcode type
information (which can be locked down by the initial Boot BIOS) of the requested
command.
The Write Protect and Lock Enable bits interact in the same manner for SPI BIOS as
they do for the FWH BIOS.
Shared Flash Address Range Protection
The System Flash (BIOS) occupies the top part of the SPI Flash Memory Device when
sharing this space with the LAN and Manageability functions. To prevent the system
from inappropriately accessing or modifying information in the LAN and Manageability
areas, the ICH7 checks outgoing addresses with the BIOS Base Address register and
blocks any cycles with addresses below that value. This includes Direct Memory Reads
to the SPI flash.
Once BIOS has locked down the BIOS BAR, this mechanism remains in place until the
next system reset.
Intel^® Quick Resume Technology (Digital Home
Only)
ICH7 implements the following Intel^® Quick Resume Technology (QRT) features:
• Visual Off
• Consumer Electronics (CE) like On/Off
Visual Off
Intel Quick Resume Technology provides a new functional state called Visual Off. In
Visual Off the PC appears to be Off but is actually active and able to run program tasks.
The Visual Off state is transparent to the user. It is entered by simply pressing the
power button when the system is On. This turns off the display, sound, front panel
lights and HID devices (e.g. keyboard and mouse) but the PC stays active. Perceptually
to the user, the system appears Off in this state. Pressing the power button again will
turn back On the perceptual components that were “muted” in Visual Off.
From the Visual Off state, the system's power management can place the PC in a low
power suspend state (S3) using existing mechanisms. Again, this is transparent to the
end user.
CE-like On/Off
Intel Quick Resume Technology redefines the PC's power button behavior to switch
between user perceived On and Off states like a consumer electronics (CE) device. For
example when a television is turned off there is no shutdown procedure. The viewer
simply turns it Off. Likewise when a modern television is turned On it returns to the
same channel, volume level, color balance, etc. as when it was turned Off. Intel Quick
Resume Technology gives the PC this similar functionality. A simple press of the power
button turns it On or Off. There is no user visible lengthy boot up or shutdown process
as the Visual Off state is used. Therefore, there is no need to exit running applications.
Intel ^® ICH7 Family Datasheet
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