Component Descriptions
Model P5000HX Series CPU User’s Manual
67
The TXC interfaces with the Pentium processor host bus, a
dedicated memory data bus, and the PCI bus. The TXC
interfaces directly to the Pentium processor 3V host bus,
directly to 5V or 3V DRAMs, and directly to the 5V PCI
bus. The TXC works with the PCI IDE/ISA Xcellerator
(PIIX3) component. PIIX3 provides the PCI to ISA bridge
functions along with other features such as a Fast PCI
IDE, Plug-n-play port, APIC interface and PCI 2.1
compliant operation.
PCI ISA IDE
Xcellerator (PIIX3)
The PCI ISA IDE Xcellerator (82430HX- PIIX3) is a multi-
function PCI device implementing a PCI-to-ISA bridge
function and a PCI IDE function. In addition, the PIIX3
implements a .host/hub function. The PIIX3 integrates
many common I/O functions found in ISA-based PC sys-
tems--- a seven Channel DMA controller, two 82C59 inter-
rupt controllers, an 8254 timer/counter, and power
management support. The DMA supports compatible and
Type F transfers.
The chip select decode logic includes the BIOS, Real Time
Clock (RTC) and keyboard controller. The PIIX3 provides
support for up to four IDE devices providing an interface
for hard disks and CD ROMs. The PIIX3 provides mother-
board plug-n-Play compatibility.
Also, the PIIX3 provides an interface with host and hub
control functions and two programmable ports. The PIIX3
provides support for an external I/O APIC.
