NXP Semiconductors MC68HC908MR16CFU

Overview

MC68HC908MR16CFU from Freescale Semiconductor is an 8-bit HCS08-core microcontroller with 16 KB on-chip FLASH, 512 B RAM, and integrated motor-control PWM (PWMMC), 10-bit ADC (8+2 channels), SCI, SPI, and dual timer interfaces. It operates at up to 8 MHz bus frequency, supports 2.7–5.5 V supply, and targets embedded motor control in industrial actuators and appliance drives.

For engineers reviewing the MC68HC908MR16CFU datasheet, MC68HC908MR16CFU pinout, MC68HC908MR16CFU application, or MC68HC908MR16CFU equivalent, this page delivers verified technical context, package mapping, functional pin roles, real-world use cases, and validated alternative options for design-in and long-term sourcing.

Technical Context

The MC68HC908MR16CFU integrates a PLL-based Clock Generator Module (CGM) supporting crystal or external clock input, enabling programmable bus frequencies up to 8 MHz. Its PWMMC module provides six independent or three complementary PWM outputs with configurable dead-time insertion and motor-phase polarity sensing.

It features a 10-bit successive-approximation ADC with eight single-ended or two differential inputs, conversion time of 12 µs (max), and internal voltage reference options. The device includes a Computer Operating Properly (COP) watchdog, Low-Voltage Inhibit (LVI), and Power-On Reset (POR) for robust operation in noisy industrial environments.

Key Specifications

Pinout & Package

MC68HC908MR16CFU is housed in a 64-pin QFP (Quad Flat Package) with 0.5 mm pitch, thermally enhanced for motor-control thermal cycling. Pin functions are defined per Freescale Document MC68HC908MR32/MR16 Data Sheet, Rev. 6.1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC68HC908MR16CFU, MC9RS08KA8CFD offers lower unit cost but sacrifices motor-control integration and real-time determinism, while MC56F8037VLD delivers higher computational throughput at increased system complexity and power consumption.

Availability

MC68HC908MR16CFU is available at Aetrix Electronics and suitable for industrial motor drives, home appliance control systems, and automotive auxiliary modules requiring stable component supply across extended product lifecycles.

Supply support for MC68HC908MR16CFU 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

Freescale Semiconductor (now part of NXP Semiconductors) pioneered HCS08 architecture for cost-sensitive, high-reliability embedded control applications.

The MC68HC908MR16CFU belongs to the MR-series motor-control MCU family, designed specifically for single-chip implementation of sensorless BLDC/PMSM drives and precision actuator control in harsh electrical environments.

FAQ

What is the maximum operating frequency of the MC68HC908MR16CFU?

The MC68HC908MR16CFU supports a maximum bus frequency of 8 MHz, achieved via its integrated PLL-based Clock Generator Module (CGM). This frequency is derived from a crystal (1–8 MHz) or external clock source, with programmable multiplication factors. The core executes instructions at this bus rate, enabling deterministic real-time response for motor commutation and ADC sampling within tight timing windows.

Does the MC68HC908MR16CFU support in-system programming (ISP)?

Yes, the MC68HC908MR16CFU supports full in-system programming via its on-chip monitor ROM. Using the background debug mode (BDM) through PTA7, firmware updates can be performed without removing the device from the PCB. FLASH memory supports page erase, mass erase, and byte/word programming - all executed under user code control with no external programmer required.

How many ADC input channels does the MC68HC908MR16CFU have, and what is their resolution?

The MC68HC908MR16CFU integrates a 10-bit successive-approximation ADC with ten total analog input channels: eight single-ended (AN0–AN7) and two differential (AN8/AN9). Conversion time is guaranteed at ≤12 µs across the full 2.7–5.5 V supply range, and the module supports hardware-triggered conversions synchronized to PWM events for precise current-sensing timing.

What PWM configurations are supported by the MC68HC908MR16CFU's PWMMC module?

The MC68HC908MR16CFU's Pulse-Width Modulator for Motor Control (PWMMC) supports six independent PWM outputs or three complementary PWM pairs. Complementary mode includes programmable dead-time insertion (128 ns to 12.8 µs) and automatic fault shutdown on overcurrent or undervoltage conditions. Top/bottom correction logic adjusts PWM timing based on motor-phase current polarity sensed via differential ADC inputs.

Is the MC68HC908MR16CFU pin-compatible with the MC68HC908MR32CFU?

Yes, the MC68HC908MR16CFU is pin-compatible with the MC68HC908MR32CFU. Both devices share identical 64-pin QFP packaging, identical pin assignments, and identical peripheral register maps. The only functional difference is FLASH size (16 KB vs. 32 KB); all I/O, ADC, PWM, timer, and communication peripherals operate identically, enabling seamless migration between memory variants.