1. Features

PCI Interface

− PCI Specification V. 2.1 compliant

− Supports 32-bit PCI bus & up to 33 MHz PCI

bus frequency

− Supports PERR# & SERR# Error Reporting

− Supports Delayed Transaction

− Optional CLKRUN# interface support

Programmable PCI Address Decoders

− Supports either programmable positive decode

or full subtractive decode of PCI cycles

− Provides 6 positively decoded I/O blocks & 4

positively decoded memory blocks.

− Optional support ROMCS# fast positive decoder

PC/PCI DMA Controller

− Comply with Intel Mobile PC/PCI DMA R2.2

− Supports PPDREQ# and PPDGNT#

− Provides software transparent capability

Distributed DMA Controller

− Comply with Distributed DMA R6.0

− Supports 7 DDMA channels

− Optional DDMA-Concurrent PCI bus

ISA Interface

− Supports full ISA compatible functions

− Supports ISA at ¼ of PCI frequency

− ISA Bus Master supported

− Supports 4 ISA slots

SM Bus

− Comply with System Management Bus

Specification R. 1.0

− Supports single master mode

− Interface to Serial E2PROM

Serial IRQ

− Comply with Serialized IRQ Support for PCI

system R6.0

− Supports both continuous and quite modes

− Auto detect Start Frame width and slot

number

− Encodes all ISA IRQs and IOCHCK#

Optional FLASH ROM Interface

− Supports up to 1 Mbytes ROM size

− Positively fast decodes F-segments by poweron

strapping

Versatile power-on strapping options

Supports NOGO function

Single 33 MHz Clock Input

+3.3V PCI I/F with +5V tolerant I/O buffers

+5V ISA I/F and core Power Supply

Package: 160 TFBGA

2. General Description

The IT8888G is a PCI to ISA bridge single function device. The IT8888G serves as a bridge between the PCI bus

and ISA bus. The IT8888G’s 32-bit PCI bus interface is compliant with PCI Specification V2.1 and supports both

PCI Bus Master & Slave. The PCI interface supports both programmable positive and full subtractive decoding

schemes.

The IT8888G also integrates two enhanced DMA Slave controllers for achieving PCI DMA cycles: PC/PCI DMA

Slave Controller & Distributed DMA Slave Controllers.

The IT8888G also implements the optional fast positive decode of F, E, D, C memory segments. This special

feature can provide a direct connection to an FALSH boot ROM.

The NOGO function, which is also implemented in the IT8888G for enabling or disabling subtractive decode of PCI

interface, could be a software controlled output pin from other host controlled devices. The Serial IRQ is also

implemented in the device for sending and receiving ISA IRQs & IOCHCK#. The device includes an ISA interface

which supports full ISA compatible functions.

The IT8888G is available in 160-pin TFBGA package.