The Piix4, Pci/Isa Bridge Chip (82371Ab) - HP Kayak XA Technical Reference Manual

2 System Board
Chip-Set

The PIIX4, PCI/ISA Bridge Chip (82371AB)

The universal host controller interface (UHCI) chip, known as PIIX4, is
encapsulated in a Ball Grid Array (BGA) package.
The PIIX4 chip is a multi-function PCI device implementing a PCI-to-ISA
bridge function, a PCI IDE function, a Universal Bus host/hub function, and
an Enhanced Power Management function.
The following figure shows an example of the system block diagram using
the PIIX4 chip.
Host Bus
Cirrus AGP
CL5465
PCI Bus (3.3V or 5V, 30/33 MHz)
Hard Disk Hard Disk
BMI IDE
Ultra DMA/33
CD-ROM
ISA/EIO Bus (3.3V; 5V T olerant)
32
Second Level
Processor
Cache
Host-to-PCI
AGP Bus
Bridge
PCI/ISA Bridge (PIIX4)
82371AB
Main Memory
Memory Bus
DRAM
USB 1
PCI Slots
USB2
GP[I,O] (30+)
SM Bus
Audio
KBD
FDC, IR
BIOS
SP , PP ,