Information Technology Reference
In-Depth Information
5.2
TX motherboard
The Intel 430HX motherboard only supports up to 128 MB of memory and has a relatively
small second level cache (256 kB). The Intel 430TX board has many enhanced devices, such
as standardised USB connections and enhanced super I/O device. Figure 5.9 shows the main
layout. The 430TX board uses 168-pin DIMM sockets for memory addition. It supports both
EDO DRAM and SDRAM (synchronous DRAM). SDRAM synchronous data transfers using
the system clock. This simplifies memory timing, leading to an increase in memory transfer.
The 430TX motherboard supports a 64-bit data path to memory.
The 430TX board uses the 82430TX PCI chipset, which has:
•
82439TX Xcelerated Controller (MTXC), which replaces the TXC (82439HX) in the
HX board.
•
82371AB PCI/ISA IDE Xcelerator (PIIX4), which replaces the PIIX3 (82371SB) in the
HX board. This is a 324-pin BGA that integrates PCI-to-ISA bridge (two 82C37 DMA
controllers, two 82C59 interrupt controllers, an 82C54 timer/counter and a real-time
clock), PCI/IDE interface, USB host/hub function and power management functions.
Audio
codec
Audio
(OP4-ML)
Level 2 cache
SRAM
Pentium
processor
Video
capture
processor
PCI
connectors
82430TX
System
Controller
TV-out
device
ISA
connectors
82430TX
PCI/ISA/IDE
Xcelerator (PIIX4)
DIMM
sockets
Flash
memory
device
PC87307UL
I/O Controller
Video
m
e
m
ory
Graphics
controlle
r
IDE
connectors
Figure 5.9
AN430TX board
5.2.1 PIIX4
The PIIX4 supports two types of PCI DMA protocol, PC/PCI DMA which uses dedicated
request and grant signals to permit PCI devices to request transfers associated with specific
