W83769
LOCAL BUS IDE SOLUTION
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
· 100% PCI Local Bus 2.0 compatible
· IDE primary/secondary address selection
· 32-bit local bus interface
· Automatic standby mode for power saving
· On-chip decode and select logic
· Supports local bus operation at up to 50 MHz
· Four-level pipelined read-ahead and four-level posted write buffers for concurrent system
operations
· Programmable parameters for command active and recovery timing
· Direct supports four IDE disk drives
· Programmable address setup timing and data active/recovery timing for each drive
· Slew-rate-controlled direct driving capability to interface with IDE disk
· Drivers for DOS, Windows, Novell, and OS/2
· Supports ATA 3.0 IDE standard
· Packaged in 100-pin PQFP
Publication Release Date: September 1994
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Revision A1