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.