NXP Semiconductors MCF51MM256CLL

Overview

MCF51MM256CLL from NXP Semiconductors (formerly Freescale) is a 32-bit ColdFire V1 microcontroller featuring a 256 KB flash memory, 32 KB RAM, and integrated measurement engine including 16-bit SAR ADC (4 differential/8 single-ended channels), 12-bit DAC, dual op-amps, dual trans-impedance amplifiers, and programmable delay block (PDB). It operates up to 50.33 MHz at ≥2.4 V across –40°C to +105°C and supports USB On-The-Go, Mini-FlexBus, dual SCI, dual SPI, I²C, TPM timers, and ultra-low-power stop modes - deployed in handheld metering devices requiring analog sensing, signal conditioning, and embedded connectivity.

For engineers reviewing the MCF51MM256CLL datasheet, MCF51MM256CLL pinout, MCF51MM256CLL application, or MCF51MM256CLL equivalent, this page delivers verified technical context, package-specific pin assignments, real-world use cases in energy metering and portable instrumentation, and validated alternative MCUs with documented functional and packaging differences.

Technical Context

The MCF51MM256CLL implements the ColdFire Instruction Set Architecture Revision C (ISA_C) with 32-bit MAC support for signed/unsigned integer and fractional arithmetic. Its Multipurpose Clock Generator (MCG) integrates PLL and FLL with internal reference trimming (0.2% resolution, ±0.5% to –1% deviation over voltage/temperature), enabling CPU frequencies from 4 kHz to 50 MHz.

On-chip peripherals include dual 4-channel Timer/PWM Modules (TPM1/TPM2), carrier modulator timer (CMT) for infrared output, real-time debug via ColdFire DEBUG_Rev_B+ interface with 6 hardware breakpoints, and hardware CRC acceleration. The measurement engine coordinates ADC sampling and DAC output via PDB-triggered sequences, supporting synchronized sensor biasing and acquisition in stop3 mode.

Key Specifications

Pinout & Package

Package: 100-pin LQFP (14 mm × 14 mm), RoHS-compliant, lead-free, moisture sensitivity level 3.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 32-bit microcontroller applications.

Compared with K22FN512VLH12 and MCF52259CAG80, the MCF51MM256CLL offers optimal integration of metrology-grade analog peripherals (TRIAMP, PDB-synchronized ADC/DAC) in a compact 100-pin LQFP, making it uniquely suited for cost-sensitive, battery-operated metering where mixed-signal precision outweighs raw compute throughput.

Availability

MCF51MM256CLL is available at Aetrix Electronics and suitable for smart energy metering, portable medical instrumentation, and industrial process monitoring requiring stable component supply, long-term lifecycle support, and guaranteed traceability.

Supply support for MCF51MM256CLL 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, delivering secure, scalable, and energy-efficient microcontrollers for industrial and automotive markets.

The MCF51MM256CLL belongs to the ColdFire V1 family - designed specifically for handheld metering devices demanding high analog integration, ultra-low-power operation, and robust real-time performance in constrained form factors.

FAQ

What is the maximum operating frequency of the MCF51MM256CLL and under what voltage conditions?

The MCF51MM256CLL achieves up to 50.33 MHz at supply voltages ≥2.4 V, 40 MHz at ≥2.1 V, and 20 MHz at ≥1.8 V - all fully specified across the industrial temperature range (–40°C to +105°C). This voltage-frequency scaling allows dynamic power optimization in battery-powered MCF51MM256CLL designs without sacrificing real-time responsiveness.

Does the MCF51MM256CLL support USB device, host, and OTG modes simultaneously?

Yes, the MCF51MM256CLL implements a true dual-role USB On-The-Go (OTG) controller compliant with USB Specification 2.0. It supports device, host, and OTG configurations in firmware, with automatic role negotiation via ID pin detection and integrated 3.3 V regulator powering the PHY - all managed within the MCF51MM256CLL silicon.

How many analog input channels does the 16-bit ADC in the MCF51MM256CLL support, and what configurations are available?

The MCF51MM256CLL's 16-bit SAR ADC supports up to four differential input pairs (eight pins) and eight single-ended inputs (shared with differential pins), for a total of 12 unique analog input channels. It includes range-compare function, internal bandgap reference, and operates down to 1.8 V - all confirmed in the MCF51MM256CLL datasheet Rev. 5, Table 15–17.

Can the MCF51MM256CLL operate in ultra-low-power modes while maintaining analog functionality?

Yes, the MCF51MM256CLL supports stop3 mode where the Time-of-Day (TOD) counter, PRACMP analog comparator, ADC, VREFO reference, and DAC remain operational with typical wake-up time of 6 µs. This enables event-driven sensing (e.g., wake-on-threshold) in battery-powered MCF51MM256CLL applications without compromising accuracy or latency.

What debug interface does the MCF51MM256CLL provide, and is external hardware required?

The MCF51MM256CLL integrates ColdFire DEBUG_Rev_B+ interface using a single-wire Background Debug Mode (BDM) connection on PTD0/BKGD/MS pin. No external JTAG emulator is needed - standard S08-family debug modules are electrically compatible, enabling full real-time debug, flash programming, and trace buffer access directly through the MCF51MM256CLL's native interface.