Renesas IS82C54Z96

Overview

IS82C54Z96 from Intersil is a CMOS programmable interval timer IC with three independent 16-bit counters, supporting up to 8MHz clock input, binary or BCD counting, six programmable modes, and TTL-compatible 5V operation. It serves as a system timing peripheral in legacy x86 embedded controllers for real-time clock generation, event counting, and programmable rate generation.

For engineers reviewing the IS82C54Z96 datasheet, IS82C54Z96 pinout, IS82C54Z96 application, or IS82C54Z96 equivalent, this device delivers deterministic timing control in industrial PLCs, military avionics timing modules, and retro-computing platform replacements where NMOS 8254 compatibility and low-power static CMOS operation are required.

Technical Context

The IS82C54Z96 implements three fully independent synchronous down-counters, each with dedicated CLK, GATE, and OUT terminals, and shares a common 8-bit bidirectional data bus (D0–D7), address decoding (A0/A1), and control interface (RD/WR/CS). Its internal architecture includes a Control Word Register, status latch, and per-counter output latches (OLM/OLL) and count registers (CRM/CRL) enabling non-disruptive read-back of live counter values and mode/status.

It supports all six standard 8254 timer modes-including Mode 0 (interrupt on terminal count), Mode 2 (rate generator), and Mode 3 (square wave)-with precise timing defined by AC parameters such as TCLK = 125 ns (8 MHz), TOD ≤ 150 ns, and TGW ≥ 50 ns. The device operates across –40°C to +85°C and requires only a single +5V supply with ICCOP ≤ 10 mA at 8 MHz.

Key Specifications

Pinout & Package

IS82C54Z96 is supplied in a 24-lead PDIP package (Pb-free, RoHS-compliant), with through-hole mounting and wave-solder compatible termination. Pin 12 and Pin 24 are GND and VCC respectively; all I/O pins meet TTL voltage thresholds and drive specifications.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar programmable timer applications.

Compared with IS82C54-10Z96 and DS82C54Z96, the IS82C54Z96 offers optimal cost-performance balance for 8 MHz-class embedded timing, retains full backward compatibility with legacy 8254 firmware, and provides guaranteed long-term supply under Intersil's extended product support program.

Availability

IS82C54Z96 is available at Aetrix Electronics and suitable for industrial PLC timing modules, military avionics synchronization circuits, retro-computing platform replacements, and legacy medical equipment maintenance requiring stable component supply over extended production lifecycles.

Supply support for IS82C54Z96 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 precision analog, power management, and timing solutions before its acquisition by Renesas Electronics in 2017.

The IS82C54Z96 belongs to Intersil's CMOS programmable timer family, designed specifically to replace power-hungry NMOS 8254s in embedded control systems while maintaining full software and hardware compatibility.

FAQ

What is the maximum clock frequency supported by the IS82C54Z96?

The IS82C54Z96 supports a maximum clock input frequency of 8 MHz, as confirmed by AC Electrical Specifications on page 4 of FN2970 Rev 6.00. This corresponds to a minimum clock period (TCLK) of 125 ns. Exceeding this limit may result in undefined counter behavior or failure to meet timing guarantees for output delay (TOD ≤ 150 ns) and gate setup (TGS ≥ 50 ns).

Does the IS82C54Z96 support BCD counting mode?

Yes, the IS82C54Z96 supports both binary and BCD counting modes. The BCD bit (D0) in the Control Word determines format: when set to '1', the counter operates as a 4-decade BCD counter (0000–9999); when '0', it functions as a 16-bit binary counter (0000–65535). This capability is explicitly listed in the Features section and validated in the Control Word Format table on page 8.

Is the IS82C54Z96 pin-compatible with the original NMOS 8254?

Yes, the IS82C54Z96 is fully pin-compatible and functionally equivalent to the NMOS 8254. The datasheet states "Compatible with NMOS 8254" and confirms identical pin assignments, signal definitions, and programming model. This allows direct replacement in existing designs without PCB or firmware changes, provided the +5V supply and temperature range align.

What is the operating temperature range for the IS82C54Z96?

The IS82C54Z96 is rated for operation from –40°C to +85°C, corresponding to the IX82C54 grade per the Ordering Information table on page 2. This extended temperature range qualifies it for industrial control cabinets, avionics bays, and outdoor deployed equipment where ambient conditions exceed commercial-grade limits.

How does the Read-Back command work on the IS82C54Z96?

The Read-Back command (Control Word with SC1/SC0 = 11 and D5/D4 = 00) allows software to simultaneously latch count values and status flags (OUTPUT, NULL COUNT, mode bits) for one or more counters. Once latched, subsequent reads return the frozen snapshot until the counter is reprogrammed or another Read-Back is issued-enabling reliable diagnostics without disrupting real-time timing operations.