Service manual

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Chipset
SOUTH BRIDGE, PCI ISA IDE XCELERATOR, 82371EB (PIIX4E)
The PCI ISA IDE Xcelerator (PIIX4E) is a multi-function PCI device implementing a PCI-to-ISA bridge function, a
PCI IDE function, a Universal Serial Bus host/hub function, and an Enhanced Power Management function. As a
PCI-to-ISA bridge, the PIIX4E 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 a Real Time Clock. In
addition to compatible transfers, each DMA channel supports Type F transfers. The PIIX4E also contains full
support for both PC/PCI and Distributed DMA protocols implementing PCI based DMA. The Interrupt Controller
has Edge or Level sensitive and programmable inputs and fully supports the use of an external I/O Advanced
Programmable Interrupt Controller (APIC) and Serial Interrupts. Chip select decoding is provided for BIOS, Real
Time Clock, Keyboard Controller, second external Microcontroller, as well as 2 Programmable Chip Selects. The
PIIX4 provides full Plug and Play compatibility. The PIIX4E can be configured as a Subtractive Decode bridge. This
allows the use of a subtractive decode PCI-to-PCI bridge such as the 82380 chipset which implements a PCI/ISA
docking station environment.
The PIIX4E supports two IDE connectors for up to four IDE devices providing an interface for IDE hard disks and
ROMs. Up to four IDE devices can be supported in Bus Master mode. The PIIX4E contains support for “Ultra
DMA” synchronous DMA compatible devices.
The PIIX4E contains a Universal Serial Bus (USB) Host Controller that is Universal Host Controller Interface
(UHCI) compatible. The Host Controller’s root hub has two programmable USB ports.
The PIIX4E supports Enhanced Power Management, including full Clock Control, Device Management for up to
14 devices, and Suspend and Resume logic with Power On Suspend, Suspend to RAM or Suspend to Disk. It fully
supports Operating System Directed Power Management via the Advanced Configuration and Power Interface
(ACPI) specification. The PIIX4E integrates both a System Management Bus (SMBus) Host and Slave interface for
serial communication with other devices.
core logic chipset
Features
• Supports Pentium and Pentium II Microprocessors
- 440BX ISA kit
• Power Management Logic
- Global and local device management
- Suspend/resume logic
- Supports thermal alarm
- Support for external microcontroller
- Full support for Advanced Configuration and Power Interface (ACPI) Specification and OS Directed Power Management