NEC D8259AC-2 Processor / Microcontroller IC DIP-28

NEC D8259AC-2 Processor / Microcontroller IC DIP-28

The D8259AC-2 is an interrupt controller designed to manage and prioritize multiple hardware interrupt requests for microprocessor systems. It centralizes handling of asynchronous events, reducing processor overhead by managing interrupt requests, generating vectored interrupts, and supplying a prioritized response. Internally it maintains request and service registers that track pending and serviced interrupts, enabling precise control over interrupt acknowledgement and masking.

Built for straightforward integration, the device supports cascading to expand interrupt capacity, allowing a master–slave arrangement where one master can control multiple slave controllers. Its programmable interface permits initialization and mode selection through defined control words, while its internal priority resolution supports flexible schemes to match system requirements. The chip interfaces directly with CPU interrupt acknowledge cycles to supply vector information.

Physically available in a 28-pin DIP package, the UPD8259A is compatible with TTL logic levels and standard +5V operation common to legacy microprocessor platforms. Its compact form and predictable behavior make it suitable for embedded and general-purpose systems where deterministic interrupt handling is required. Its simple programming model, clear signal timing, and support for both edge and level-triggered events simplify system design and debugging across a wide range of legacy platforms.

Features:

• Programmable interrupt controller with vectored interrupts.
• Eight independent interrupt request inputs (IR0–IR7).
• Supports master/slave cascading to expand to 64 IRQ lines.
• Maskable interrupts with individual IRQ masks.
• Priority resolver with multiple selectable priority schemes.
• Request, In-Service, and Interrupt Mask registers for control.
• Initialization Control Words (ICWs) and Operation Control Words (OCWs) for programming.
• Interfaces to processor interrupt-acknowledge cycles to supply vector information.
• TTL-level compatible inputs and outputs for direct logic interfacing.
• Offered in a standard 28-pin DIP package for legacy/through-hole systems.

Specifications:

Pin Configuration:

Applications:

• Microprocessor-based systems.
• Embedded controllers.
• I/O interrupt management.
• Real-time control systems.
• Telecommunications equipment.
• Industrial automation.

Package Contents:

• 1x NEC D8259AC-2 Processor / Microcontroller IC DIP-28

Datasheet