W83769

LOCAL BUS IDE SOLUTION

Publication Release Date: September 1994

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Revision A1

GENERAL DESCRIPTION

The W83769 is a high-performance, low-cost, highly integrated logic design for IDE hard disk

applications in PCI (Peripheral Component Interconnect) local bus systems. It provides a bridge

between a standard IDE drive and the PCI local bus. The W83769 is fully compatible with the ANSI

ATA 3.0 specifications for IDE hard disk operation and the PCI SIG revision 2.0 specifications for the

PCI local bus protocol. Packaged in a 100-pin PQFP, the W83769 directly supports the 32-bit PCI bus

without requiring any external TTLs.

The W83769 operates at up to 50 MHz and provides a full 32-bit data path to the PCI bus. Double-

word read and write operations are provided via internal control and conversion logic. Write posting

and read-ahead allows CPU memory cycles to run concurrently with IDE cycles and improves the

hard disk buffer-to-host transfer rate.

The IDE drive interface timing of the W83769 is completely software programmable, including

command active/recovery timing and address setup-hold timing for each drive. The device

supports Fast ATA/Enhanced IDE mode 3 timing and IORDY monitoring for better performance.

The W83769 directly supports four IDE drives with 170/1F0 dual IDE connectors. The IObase

addresses of the primary/secondary IDE connector are exchangeable by power-on strap option.

FEATURES

operations