Renesas IP82C54

Overview

IP82C54 from Intersil is a CMOS programmable interval timer IC with three independent 16-bit counters, 8MHz clock input capability, TTL-compatible I/O, and operation across –40°C to +85°C. It serves as a system timing peripheral in legacy x86 embedded controllers for real-time clock generation, event counting, and programmable rate control.

For engineers reviewing the IP82C54 datasheet, IP82C54 pinout, IP82C54 application, or IP82C54 equivalent, this page delivers verified functional identity, validated PDIP-24 package mapping, confirmed counter-mode behavior, exact DC/AC timing specs per Intersil FN2970 Rev 6.00, and two industry-recognized drop-in alternatives.

Technical Context

The IP82C54 implements three fully independent synchronous down-counters, each configurable via an 8-bit control word into six distinct modes (Mode 0–5), supporting binary or BCD counting. Its read/write logic decodes A0/A1 to select Counter 0/1/2 or the Control Word Register, with CS, RD, and WR enabling standard microprocessor bus interfacing.

It features status read-back capability (latching count, mode, OUT state, and null-count flag), output latching on command, and static CMOS design ensuring low ICCSB = 10µA standby current. All counters operate from a single +5V supply (4.5V–5.5V) and tolerate full TTL voltage levels.

Key Specifications

Pinout & Package

IP82C54 is packaged in a 24-lead plastic dual in-line package (PDIP), RoHS-compliant Pb-free plus anneal variant available (IP82C54Z). Pinout conforms to industry-standard 8254 layout and supports direct replacement of NMOS 8254 in legacy designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with NE8254, IP82C54 reduces operating current by >60% and adds standby mode; compared with ICS82C54, it offers identical functionality at lower cost but with slightly relaxed AC timing margins per FN2970 Rev 6.00.

Availability

IP82C54 is available at Aetrix Electronics and suitable for industrial control systems, legacy x86 embedded platforms, and test equipment requiring stable component supply with long-term lifecycle support.

Supply support for IP82C54 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 ICs before its acquisition by Renesas Electronics in 2017.

The 82C54 product line was designed as a CMOS upgrade to the industry-standard 8254 timer, targeting backward-compatible integration into 80C86/80C88-based systems with reduced power and extended temperature range.

FAQ

What is the maximum clock frequency supported by the IP82C54?

The IP82C54 supports a maximum clock input frequency of 8MHz per counter channel, as specified in Intersil's FN2970 Rev 6.00 datasheet. This corresponds to a minimum clock period of 125ns and enables precise timing intervals down to the nanosecond scale when used in Mode 2 or Mode 3 configurations. The IP82C54-10 and IP82C54-12 variants support higher frequencies, but the base IP82C54 is rated strictly at 8MHz.

Is the IP82C54 pin-compatible with the original NMOS 8254?

Yes, the IP82C54 is fully pin-compatible and functionally equivalent to the NMOS 8254, including identical pin assignments, control word format, and counter mode behavior. It is explicitly marketed as an enhanced CMOS replacement with TTL-compatible I/O, allowing direct socket replacement in existing 8254-based designs without PCB modification. The IP82C54 retains the same 24-pin PDIP footprint and signal definitions as documented in the FN2970 datasheet.

Does the IP82C54 support BCD counting, and how is it enabled?

Yes, the IP82C54 supports Binary-Coded Decimal (BCD) counting in addition to binary mode. BCD operation is enabled by setting the BCD bit (D0) to '1' in the control word written to the Control Word Register (A1=A0=11). When enabled, the counter operates in 4-decade (0000–9999) format, with automatic carry between decades. This feature is confirmed in the FN2970 Rev 6.00 datasheet under "Control Word Format" and "Functional Description" sections.

What is the operating temperature range for the IP82C54?

The IP82C54 is rated for operation from –40°C to +85°C, designated by the 'I' prefix in the Intersil ordering nomenclature (e.g., IP82C54 vs. CP82C54 for commercial 0°C to +70°C). This industrial temperature grade is verified in the "Ordering Information" and "Operating Conditions" tables of FN2970 Rev 6.00, making it suitable for deployment in harsh environmental conditions such as factory floors or outdoor instrumentation.

How does the IP82C54 handle simultaneous read-back of count and status for multiple counters?

The IP82C54 supports simultaneous read-back of count and status for up to three counters using a single read-back command with COUNT (D5=0) and STATUS (D4=0) bits set. Per FN2970 Rev 6.00 Page 10, this latches both values for all selected counters (via D3–D1 bits), and subsequent reads return status first, then latched count - enabling deterministic, non-intrusive monitoring of multiple timers in real-time systems without disrupting timing accuracy of the IP82C54.