Renesas CS82C59A-12Z96

Overview

CS82C59A-12Z96 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 systems. It operates at 12.5 MHz, features fully static CMOS design, supports cascading to 64 interrupt levels, and delivers TTL-compatible I/O with single 5V supply operation.

For engineers reviewing the CS82C59A-12Z96 datasheet, CS82C59A-12Z96 pinout, CS82C59A-12Z96 application, or CS82C59A-12Z96 equivalent, this device serves as a drop-in replacement for NMOS 8259A in legacy x86 and 8080-family embedded control systems requiring low-power, programmable priority resolution and interrupt vectoring without wait states.

Technical Context

The CS82C59A-12Z96 implements a dual-mode interrupt controller architecture supporting both edge-triggered and level-triggered IR inputs, with configurable priority resolution (fully nested, rotating, or special mask modes) and dynamic reprogramming via Initialization Command Words (ICW1–ICW4) and Operation Command Words (OCW1–OCW3). Its internal registers - Interrupt Request Register (IRR), In-Service Register (ISR), and Interrupt Mask Register (IMR) - enable real-time arbitration and masking of eight asynchronous interrupt sources.

It interfaces directly with 8-bit data buses using standard RD/WR/CS/A0 control signals, provides three cascade lines (CAS0–CAS2) for master/slave configuration, and outputs either CALL opcodes (for 8080/85) or vector bytes (for 80C86/88/286) on INTA acknowledgment. The SP/EN pin supports buffered mode transceiver control or slave identification.

Key Specifications

Pinout & Package

CS82C59A-12Z96 is housed in a 28-lead Plastic Leaded Chip Carrier (PLCC) package with Pb-free matte tin terminations, RoHS compliant, supplied in tape-and-reel format (96 units per reel).

Key Features

Applications

Equivalent & Alternatives

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

Compared with CS82C59AZ96, CS82C59A-12Z96 offers updated process qualification and packaging documentation; compared with IS82C59A-12Z96, it trades extended temperature capability for lower unit cost and tighter supply chain availability in commercial-grade applications.

Availability

CS82C59A-12Z96 is available at Aetrix Electronics and suitable for industrial PLC backplanes, legacy x86 single-board computers, avionics maintenance terminals, and military communications chassis requiring stable component supply over extended production lifecycles.

Supply support for CS82C59A-12Z96 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 (now part of Renesas Electronics) is a U.S.-based semiconductor company specializing in high-reliability analog and mixed-signal ICs for industrial, aerospace, and defense applications.

The 82C59A family was developed to replace power-hungry NMOS interrupt controllers in 1980s-era microcomputer systems, delivering CMOS efficiency while maintaining full software and pin compatibility with the industry-standard 8259A.

FAQ

What is the maximum clock frequency supported by CS82C59A-12Z96?

The CS82C59A-12Z96 is rated for operation up to 12.5 MHz, enabling "no wait-state" performance with 12.5 MHz 80C286 processors. This speed grade is confirmed in the Intersil FN2784 Rev 6.00 datasheet (p.1) and distinguishes it from 5 MHz and 8 MHz variants. Exceeding 12.5 MHz may result in timing violations during ICW/OCW writes or INTA response cycles.

Is CS82C59A-12Z96 pin-compatible with the original NMOS 8259A?

Yes, CS82C59A-12Z96 is explicitly designed as a pin-compatible, functionally equivalent CMOS replacement for the NMOS 8259A. The datasheet confirms identical pinout, voltage levels, and timing behavior (FN2784 Rev 6.00, p.1), allowing direct PCB-level substitution without layout changes or signal integrity revalidation.

Does CS82C59A-12Z96 support both 8080/85 and 80C86/88 microprocessor modes?

Yes, CS82C59A-12Z96 supports dual microprocessor modes selectable via ICW4's μPM bit: μPM = 0 configures 8080/85 mode (3-byte CALL + address), while μPM = 1 configures 80C86/88/286 mode (single vector byte). This is documented in the Functional Description (p.5) and ICW4 format (p.10) of FN2784 Rev 6.00.

What package type and lead finish does CS82C59A-12Z96 use?

CS82C59A-12Z96 uses a 28-lead Plastic Leaded Chip Carrier (PLCC) package with Pb-free matte tin termination, RoHS compliant, supplied in tape-and-reel format (96 units per reel). This is specified in the Ordering Information table (p.2) and marked as "Pb-Free" in the package notes (p.2).

Can CS82C59A-12Z96 be cascaded to support more than eight interrupt sources?

Yes, CS82C59A-12Z96 supports cascading via CAS0–CAS2 lines to expand interrupt capacity to 64 levels using multiple devices. The master/slave configuration is controlled through ICW3 and ICW4, and no additional external logic is required - a capability verified in the Functional Diagram (p.3) and Cascading section (p.6) of FN2784 Rev 6.00.