Renesas IS82C59AZ

Overview

IS82C59AZ from Intersil is a CMOS Priority Interrupt Controller designed to manage up to eight vectored, prioritized interrupt requests in 8080/85- and 80C86/88/286-based microcomputer systems. It operates at 12.5MHz max, supports edge- or level-triggered inputs, features fully static design, and delivers <1mA/MHz active current with 10µA standby. It relieves CPU polling overhead in industrial control and legacy embedded systems.

For engineers reviewing the IS82C59AZ datasheet, IS82C59AZ pinout, IS82C59AZ application, or IS82C59AZ equivalent, this page provides verified technical context, confirmed pin functions, real-world interrupt controller use cases, and two validated alternative parts for 8080/85 and 80C86-compatible designs requiring priority-based vectored interrupt handling.

Technical Context

The IS82C59AZ implements a programmable priority resolver with fully nested, rotating, and special mask modes. It uses Initialization Command Words (ICW1–ICW4) and Operation Command Words (OCW1–OCW3) to configure interrupt vectoring, cascading (up to 64 levels), and masking behavior per IR0–IR7 input.

It supports dual microprocessor modes: 8080/85 mode (3-byte CALL + 16-bit vector) and 80C86/88/286 mode (2-cycle vector-only response). Its cascade interface (CAS0–CAS2) enables master/slave configurations, while SP/EN serves as slave-program input or buffer-enable output depending on buffered mode configuration.

Key Specifications

Pinout & Package

IS82C59AZ is supplied in a 28-lead PLCC (Plastic Leaded Chip Carrier) package, Pb-free with matte tin termination (RoHS compliant), suitable for reflow soldering. Package drawing N28.45 defines mechanical dimensions and land pattern.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar priority interrupt controller applications.

Compared with Intel 8259A, IS82C59AZ offers lower power, wider temperature range, and static operation; compared with NSC 82C59A, it shares identical performance and compatibility but differs only in manufacturer branding and traceability-making it a direct functional and form-fit replacement.

Availability

IS82C59AZ is available at Aetrix Electronics and suitable for industrial PLC backplanes, legacy 8080/8085 test equipment, 80C86-based medical imaging subsystems, ruggedized avionics DAQ, and military-grade embedded controllers requiring stable component supply across extended lifecycles.

Supply support for IS82C59AZ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Intersil Corporation was a U.S.-based semiconductor company specializing in high-performance analog and mixed-signal ICs, later acquired by Renesas Electronics in 2017. Known for precision timing, power management, and interface solutions.

The 82C59A product line was developed to provide CMOS-based, low-power, drop-in replacements for NMOS interrupt controllers in 8080/85 and 80C86/88/286 systems-targeting industrial, medical, and defense applications demanding reliability and long-term availability.

FAQ

What is the maximum operating frequency of the IS82C59AZ?

The IS82C59AZ is rated for up to 12.5MHz operation, enabling "no wait-state" performance with 12.5MHz 80C286 processors. This speed grade is confirmed in the Intersil FN2784 Rev 6.00 datasheet, Page 1, and is specific to the IS82C59AZ variant with industrial temperature range (−40°C to +85°C). Lower-speed versions (8MHz, 5MHz) exist but are distinct part numbers.

Is the IS82C59AZ pin-compatible with the original NMOS 8259A?

Yes, the IS82C59AZ is explicitly designed as a pin-compatible, functionally equivalent CMOS replacement for the NMOS 8259A. The datasheet states "Pin Compatible with NMOS 8259A" on Page 1 and confirms identical pinout, signal definitions, and timing relationships-allowing direct PCB-level substitution without layout changes.

Does the IS82C59AZ support both 8080/85 and 80C86/88/286 interrupt protocols?

Yes, the IS82C59AZ supports both protocols via software-configurable ICW4 μPM bit: μPM = 0 selects 8080/85 mode (3-interrupt-acknowledge sequence delivering CALL opcode + 16-bit vector), and μPM = 1 selects 80C86/88/286 mode (2-interrupt-acknowledge sequence delivering 8-bit vector only). This dual-mode capability is documented in FN2784 Pages 7–8.

What is the purpose of the SP/EN pin on the IS82C59AZ?

The SP/EN pin on the IS82C59AZ serves dual roles: in non-buffered mode (BUF=0 in ICW4), it acts as Slave Program input (SP=1=master, SP=0=slave); in buffered mode (BUF=1), it becomes an Enable output controlling external bus transceivers. Its function is determined solely by the BUF bit in ICW4, as defined in FN2784 Page 9 and Figure 7.

What temperature range is specified for the IS82C59AZ?

The IS82C59AZ is specified for −40°C to +85°C operation, qualifying it for industrial environments. This is confirmed in the Ordering Information table on Page 2 of FN2784 Rev 6.00, where IS82C59AZ is listed under the "IS82C59A" family row with TEMP RANGE (°C) = "−40 to +85". Commercial (0°C to +70°C) and military variants exist but are different part numbers.