NXP Semiconductors MCF51EM128CLL

Overview

MCF51EM128CLL from NXP Semiconductors (formerly Freescale) is a 32-bit ColdFire V1 RISC microcontroller designed for ultra-low-power embedded applications requiring integrated LCD driving, real-time clock, and mixed-signal peripherals. It features 128 KB flash, 16 KB RAM, 50.33 MHz CPU operation at 3.6–2.5 V, <1.3 μA battery-mode current, and operates across –40°C to +85°C in an 80-pin LQFP package. It is used in portable medical devices, industrial HMI panels, and smart utility meters where power efficiency and on-chip display control are critical.

For engineers reviewing the MCF51EM128CLL datasheet, MCF51EM128CLL pinout, MCF51EM128CLL application, or MCF51EM128CLL equivalent, key selection considerations include its dual crystal oscillator support (XOSC1 for IRTC, XOSC2 for core), programmable delay block (PDB) for synchronized ADC sampling, independent RTC with tamper detection, and 4-channel 16-bit SAR ADC with differential inputs - all validated for stop3 low-power mode operation.

Technical Context

The MCF51EM128CLL implements the ColdFire V1 core with ISA_C instruction set and hardware MAC unit optimized for 16×16±32 signed/unsigned integer or fractional operations. Its system integration includes a dual-oscillator architecture: XOSC1 (32.768 kHz) powers the independent real-time clock (IRTC) in a separate voltage domain, while XOSC2 drives the internal clock source (ICS) with frequency-locked-loop (FLL) for CPU frequencies up to 50.33 MHz.

Peripherals are partitioned for low-power operation: the PDB provides precise trigger coordination for four ADC modules; PRACMP1 and PRACMP2 analog comparators operate in stop3 mode with selectable interrupt edges; and the LCD controller supports up to 160 segments (4×40) with internal charge pump, blink functionality, and contrast trimming - all functional without MCU core activation.

Key Specifications

Pinout & Package

80-pin LQFP package (14 mm × 14 mm), RoHS-compliant, with exposed pad for thermal dissipation. Pin functions are multiplexed per Table 4 of the datasheet; unused pins on 80-pin variant are automatically disabled for reduced leakage current.

Key Features

Applications

Equivalent & Alternatives

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

Compared with Kinetis KL27Z128VLH4 and MSP430FR5969IPN, the MCF51EM128CLL uniquely combines ColdFire performance, integrated LCD driving, and independent calendar RTC - making it irreplaceable in cost-sensitive, display-centric, battery-operated designs where peripheral integration reduces BOM and layout complexity.

Availability

MCF51EM128CLL is available at Aetrix Electronics and suitable for portable medical monitors, industrial HMI panels, and smart utility meters requiring stable component supply, long-term lifecycle support, and consistent parametric performance across temperature and voltage ranges.

Supply support for MCF51EM128CLL 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, emphasizing industrial control, automotive, and ultra-low-power embedded solutions with long-term product roadmaps.

The MCF51EM128CLL belongs to the ColdFire EM series - designed specifically for battery-powered human-interface and measurement applications requiring integrated LCD, ultra-low-power RTC, and mixed-signal peripherals without external support ICs.

FAQ

What is the maximum operating frequency of the MCF51EM128CLL and under what conditions?

The MCF51EM128CLL achieves a maximum CPU frequency of 50.33 MHz when supplied between 3.6 V and 2.5 V, across the full industrial temperature range (–40°C to +85°C). At lower voltages (3.6 V to 1.8 V), the maximum frequency is reduced to 20 MHz. These ratings are specified in Section 1.3.1 of the datasheet and validated for continuous operation under worst-case thermal conditions.

Does the MCF51EM128CLL support true pin-compatible migration from the MCF51EM256CLL?

No - the MCF51EM128CLL uses an 80-pin LQFP package, while the MCF51EM256CLL is offered in a 100-pin LQFP. Although both share identical pin functions where overlapping, the 20 additional pins on the 100-pin variant (e.g., AD4, DADP0–DADM3, LCD16–LCD20) are absent on the MCF51EM128CLL. PCB redesign is required for migration.

Can the MCF51EM128CLL's ADC operate during ultra-low-power stop modes?

Yes - all four ADC modules in the MCF51EM128CLL remain fully functional in stop3 mode. The programmable delay block (PDB) can autonomously trigger conversions without CPU intervention, and results are stored in RAM. This capability is confirmed in Section 1.3.1 and Table 1 of the datasheet for the 80-pin variant.

What LCD configurations does the MCF51EM128CLL support, and how many segments are available?

The MCF51EM128CLL supports up to 160 LCD segments in a 4×40 configuration (4 backplanes, 40 frontplanes), as documented in Section 1.3.1 and Table 1. It does not support the 288-segment (8×36) mode available on the 100-pin variant due to fewer available LCD pins (37 vs. 44 segments).

Is the IRTC in the MCF51EM128CLL truly independent, and does it retain time during full power loss?

Yes - the IRTC operates in a physically separate power domain with dedicated VBAT and XOSC1 (32.768 kHz) crystal input. When VDD is removed, the IRTC continues running using battery backup, retaining calendar time, tamper status, and its 32 bytes of dedicated RAM - verified in Sections 1.3 and 2.11 of the datasheet.