NXP Semiconductors MCF51AC256BVFUE

Overview

MCF51AC256BVFUE from NXP Semiconductors (formerly Freescale) is a 32-bit ColdFire V1 microcontroller without CAN interface, housed in a 64-pin QFP package (14 mm × 14 mm), operating up to 50.33 MHz at 2.7–5.5 V supply, featuring 256 KB flash, 32 KB SRAM, 24-channel 12-bit ADC, and dual flexible timer modules - deployed in industrial motor control and sensor fusion edge nodes.

For engineers reviewing the MCF51AC256BVFUE datasheet, MCF51AC256BVFUE pinout, MCF51AC256BVFUE application, or MCF51AC256BVFUE equivalent, key selection considerations include its CAN-free configuration, 64-pin QFP mechanical footprint, V1 ColdFire ISA_C instruction set compliance, and support for real-time debug via single-wire BDM - critical for legacy ColdFire migration and cost-optimized embedded control.

Technical Context

The MCF51AC256BVFUE implements the ColdFire V1 core with instruction set revision C (ISA_C), delivering 0.76 DMIPS/MHz when executing from flash and 0.94 DMIPS/MHz from SRAM. Its multipurpose clock generator (MCG) supports FLL/PLL operation with trimmable internal reference (0.2% resolution), crystal oscillator (1–16 MHz), and independent LPO for COP/RTI.

It integrates two flexible timer modules (FTM1 and FTM2) supporting input capture, output compare, edge-aligned and center-aligned PWM, deadtime insertion, and hardware-triggered ADC conversions. The 24-channel 12-bit ADC operates asynchronously for low-noise acquisition and includes on-chip temperature sensing and automatic threshold comparison with interrupt generation.

Key Specifications

Pinout & Package

Package: 64-pin QFP, 14 mm × 14 mm, 0.8 mm pitch, RoHS-compliant (Pb-free).

Key Features

Applications

Equivalent & Alternatives

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

Compared with MCF51AC256AVFUE, the MCF51AC256BVFUE removes CAN hardware to reduce cost and die size while retaining identical timing, memory, and peripheral capabilities for standalone control. Against Kinetis K22FN512VLH12, it offers proven ColdFire toolchain continuity and lower power at 50 MHz but lacks floating-point and modern security features.

Availability

MCF51AC256BVFUE is available at Aetrix Electronics and suitable for industrial motor control, smart sensor nodes, automotive body electronics, and PLC I/O modules requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for MCF51AC256BVFUE 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 is a global semiconductor leader focused on secure connectivity solutions for automotive, industrial, and IoT markets, formed from the spin-off of Freescale Semiconductor in 2015.

The MCF51AC256 series belongs to NXP's legacy ColdFire microcontroller portfolio, designed specifically for cost-sensitive, high-reliability embedded control applications requiring deterministic real-time performance and long-term supply stability.

FAQ

What is the maximum operating frequency of the MCF51AC256BVFUE?

The MCF51AC256BVFUE operates at a maximum core frequency of 50.33 MHz across its full voltage range (2.7 V to 5.5 V). This speed is achievable with the internal FLL or PLL enabled using an external crystal (1–16 MHz) or internal reference. Performance is verified per Freescale Document Number MCF51AC256 Rev.7, Section 1.3.1, and supports 0.76 DMIPS/MHz when executing from flash memory. The MCF51AC256BVFUE maintains timing compliance under all specified temperature conditions (–40°C to +105°C).

Does the MCF51AC256BVFUE include a CAN interface?

No, the MCF51AC256BVFUE does not include a CAN interface. The 'B' in the part number explicitly denotes the CAN-disabled variant, confirmed in Table 1 (Device Comparison) and Section 1.4 (Part Numbers) of the MCF51AC256 datasheet Rev.7. Pins PTA0 (TxCAN) and PTA1 (RxCAN) are unconnected in this version, eliminating the need for CAN transceivers, termination resistors, or filtering components in the design. For CAN-enabled operation, use MCF51AC256AVFUE instead.

What package type and dimensions does the MCF51AC256BVFUE use?

The MCF51AC256BVFUE uses a 64-pin QFP package measuring 14 mm × 14 mm with 0.8 mm lead pitch, as documented in Figure 3 and Table 22 (Package Information) of the MCF51AC256 Rev.7 datasheet. It is RoHS-compliant and Pb-free. This package is mechanically identical to the 64-pin LQFP variant (MCF51AC256BVPUE) but differs in lead finish and moisture sensitivity level - both share identical pinout and thermal characteristics.

How much flash and SRAM memory does the MCF51AC256BVFUE provide?

The MCF51AC256BVFUE integrates 256 KB of on-chip flash memory and 32 KB of static RAM (SRAM), as specified in Table 1 (Device Comparison) and Section 1.3.1 of the MCF51AC256 Rev.7 datasheet. Flash supports read/program/erase over full operating voltage and temperature ranges, with block protection for secure firmware storage. SRAM retains full functionality in all low-power stop modes, enabling fast context switching and real-time data buffering without external memory.

What debug interface does the MCF51AC256BVFUE support?

The MCF51AC256BVFUE supports a single-wire background debug mode (BDM) interface via the BKGD/MS pin, providing full real-time debug capability including 6 hardware breakpoints (4 PC, 1 address pair, 1 data), on-chip trace buffer, and debug visibility bus (VBUS) for program trace. This interface is part of the ColdFire V1 core architecture and requires only one PCB trace - no JTAG header or multi-pin connector needed. Debug tools include P&E Multilink and CodeWarrior IDE.