NXP Semiconductors MCF51AC256ACPUE

Overview

MCF51AC256ACPUE from NXP Semiconductors (formerly Freescale) is a 32-bit ColdFire V1 microcontroller with CAN interface, 256 KB flash, 32 KB SRAM, and 50.33 MHz core speed, designed for industrial control and automotive body electronics requiring real-time deterministic response and robust communication.

For engineers reviewing the MCF51AC256ACPUE datasheet, MCF51AC256ACPUE pinout, MCF51AC256ACPUE application, or MCF51AC256ACPUE equivalent, key selection considerations include its 64-pin LQFP package, –40°C to +85°C temperature grade, integrated MSCAN controller, dual FTM modules with deadtime insertion, and hardware CRC accelerator for firmware integrity verification.

Technical Context

The MCF51AC256ACPUE implements the ColdFire V1 core with ISA_C instruction set, delivering 0.76 DMIPS/MHz when executing from flash and supporting background debug via single-wire BDM. Its memory subsystem includes 256 KB of on-chip flash with block protection and 32 KB SRAM with security circuitry.

System-level timing is managed by the Multipurpose Clock Generator (MCG), which supports crystal oscillator (1–16 MHz), internal reference trimming (0.2% resolution), and FLL/PLL-based frequency multiplication. The MSCAN module complies fully with CAN 2.0A/B, supporting programmable bit rates up to 1 Mbps, five receive buffers with FIFO, and bus-off recovery with time-stamped message logging.

Key Specifications

Pinout & Package

Package: 64-pin LQFP (10 mm × 10 mm, 0.5 mm pitch), RoHS-compliant, lead-free (Pb-free indicator "E" in part number).

Key Features

Applications

Equivalent & Alternatives

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

Compared with S9KEAZN64AMLH and MCF51JM128CLK, the MCF51AC256ACPUE delivers higher memory density, integrated CAN 2.0B compliance, and hardware CRC acceleration - making it uniquely suited for safety-aware, networked embedded systems requiring deterministic real-time performance and firmware integrity assurance.

Availability

MCF51AC256ACPUE is available at Aetrix Electronics and suitable for industrial motor control, automotive body electronics, and smart energy metering requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for MCF51AC256ACPUE 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

NXP Semiconductors acquired Freescale in 2015 and maintains full support for the ColdFire portfolio, including documentation, tools, and long-term supply commitments for industrial and automotive applications.

The MCF51AC256ACPUE belongs to the ColdFire V1 microcontroller family, engineered for deterministic real-time control in resource-constrained environments where CAN networking, low-power operation, and code security are mandatory design requirements.

FAQ

What is the operating temperature range for the MCF51AC256ACPUE?

The MCF51AC256ACPUE is rated for operation from –40°C to +85°C ambient temperature, validated per Freescale's industrial temperature specification. This range supports deployment in under-hood automotive modules, factory-floor controllers, and outdoor energy infrastructure where thermal stability is critical. The device includes an on-chip temperature sensor calibrated to ±3°C accuracy for system-level thermal compensation.

Does the MCF51AC256ACPUE support in-circuit debugging?

Yes, the MCF51AC256ACPUE supports single-wire background debug (BDM) via the BKGD/MS pin, enabling non-intrusive real-time debugging, flash programming, and breakpoint execution without halting the CPU. It provides six hardware breakpoints (four PC, one address pair, one data) and supports continuous or PC-profiling trace modes using the debug visibility bus (VBUS).

How many CAN message buffers does the MCF51AC256ACPUE provide?

The MCF51AC256ACPUE integrates the MSCAN module with five dedicated receive buffers organized in FIFO structure and three transmit buffers with internal prioritization based on local priority registers. Each buffer supports standard or extended identifiers, zero-to-eight-byte payloads, and time-stamped logging for diagnostic traceability.

What is the maximum ADC resolution and channel count supported by the MCF51AC256ACPUE?

The MCF51AC256ACPUE features a 12-bit successive-approximation ADC with up to 24 analog input channels. Conversion results can be formatted in 12-, 10-, or 8-bit right-justified format. The ADC supports asynchronous clocking for reduced noise and automatic compare interrupts against programmable thresholds for threshold-triggered event handling.

Is the MCF51AC256ACPUE pin-compatible with other members of the MCF51AC256 family?

Yes, the MCF51AC256ACPUE shares identical pinout and package (64-pin LQFP) with MCF51AC256BCPUE (no CAN), MCF51AC256AVPUE (–40°C to +105°C), and MCF51AC256BVPUE (no CAN, +105°C). All share the same signal mapping per pin position, enabling drop-in replacement for CAN-enabled or CAN-disabled variants within the same temperature grade.