82801DB Datasheet, PDF (86/587 Pages) Intel Corporation – Intel 82801DB I/O Controller Hub 4 (ICH4)

Functional Description
5.3
LPC Bridge (w/ System and Management Functions)
(D31:F0)
The LPC Bridge function of the ICH4 resides in PCI Device 31:Function 0. In addition to the LPC
bridge function, D31:F0 contains other functional units including DMA, Interrupt controllers,
Timers, Power Management, System Management, GPIO, and RTC. In this chapter, registers and
functions associated with other functional units (power management, GPIO, USB, IDE, etc.) are
described in their respective sections.
5.3.1 LPC Interface
The ICH4 implements an LPC interface as described in the LPC 1.0 specification. The LPC
interface to the ICH4 is shown in Figure 5-6. Note that the ICH4 implements all of the signals that
are shown as optional, but peripherals are not required to do so.
Figure 5-6. LPC Interface Diagram
PCI Bus
Intel^® ICH4
SUS_STAT#
GPI
LAD[3:0]
LFRAME#
LDRQ#
(optional)
LPCPD#
(optional)
LSMI#
(optional)
PCI
PCI
CLK RST#
PCI
PCI
SERIRQ ^PME#
Super I/O
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Intel^® 82801DB ICH4 Datasheet