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BuildOrBuy Group Network
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BuildOrBuy News -
Intel PIIX Info:  PCI ISA IDE Xcelerators

PIIX3 | PIIX4 | Ultra DMA | 430 Chipsets | Win95 FAQ

UDMA, Bus Master, Triones Bus Master drivers - Remember those in the early days of Win95? Now we have ATA/100 otherwise known as Ultra DMA - UDMA/100.... ATA/133... Serial ATA...


Intel 82371FB (PIIX) and 82371SB (PIIX3) PCI ISA IDE Xcelerator

The 82371FB (PIIX) and 82371SB (PIIX3) PCI ISA IDE Xcelerators are multi-function PCI devices implementing a PCI-to-ISA bridge function and an PCI IDE function. In addition, the PIIX3 implements a Universal Serial Bus host/hub function. As a PCI-to-ISA bridge, the PIIX/PIIX3 integrates many common I/O functions found in ISA-based PC systems.

A seven-channel DMA controller, two 82C59 interrupt controllers, an 8254 timer/counter, and power management support. In addition to compatible transfers, each DMA channel supports type F transfers. Chip select decoding is provided for BIOS, real time clock, and keyboard controller. Edge/Level interrupts and interrupt steering are supported for PCI plug and play compatibility.

The PIIX/PIIX3 supports two IDE connectors for up to four IDE devices providing an interface for IDE hard disks and CD ROMs. The PIIX/PIIX3 provides motherboard plug and play compatibility. PIIX implements two steerable DMA channels (including type F transfers) and up to two steerable interrupt lines. PIIX3 implements one steerable interrupt line. The interrupt lines can be routed to any of the available ISA interrupts. Both PIIX/PIIX3 implement a programmable chip select.


82371AB PCI-TO-ISA/IDE Xcelerator (PIIX4)

The 82371AB PCI ISA IDE Xcelerator (PIIX4) is a multi-function PCI device implementing a PCI-to-ISA bridge function, a PCI IDE function (Ultra DMA), a Universal Serial Bus host/hub function, and an Enhanced Power Management function (ACPI). As see on the Intel 430TX PCIset (Intel 82371AB PCI Bus Master IDE Controller) & Intel 440BX AGPset were both PIIX4.


Ultra DMA - Burst Mode Transfer, NOT A Sustained Rate!

Protocol for the ATA/IDE hard disk drive interface that doubles IDE/ATA drives at 16.6 MB/s to the burst data transfer rate of 33 megabytes (MB) per second (ATA/33; UDMA-33). This technology is capable of transferring twice as much data per clock cycle and provides a path for disk drive vendors to scale the performance of their products. A user can potentially benefit from faster disk reads and writes, resulting in less waiting time when starting a system or application. The Ultra DMA protocol is implemented in all new Intel PCIsets (beginning with the 430TX) and disk drive products from all leading vendors. 

  1. ATA/16 - 

  2. ATA/33 - 
  3. ATA/66 - 
  4. ATA/100 -
  5. ATA/133 - Where we are now! 
  6. Serial ATA... Expect implementation as early as Q2 - 2003. 

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Web Development, Gill Boyd & Team - Posted 07-09-2001, Revised 01/12/2003