NXP Semiconductors MC908AZ32ACFU

Overview

MC908AZ32ACFU from Freescale Semiconductor is an 8-bit HCS08-core microcontroller featuring 32 KB on-chip Flash memory, 1 KB RAM, and integrated CAN 2.0A/B controller, ADC-15 (15-channel, 10-bit), SPI, SCI, two 16-bit timer modules (TIMA/TIMB), and COP watchdog. It operates at up to 40 MHz bus frequency with internal PLL clock generation and supports automotive-grade temperature range (–40°C to +125°C) in a 64-pin QFP package.

For engineers reviewing the MC908AZ32ACFU datasheet, MC908AZ32ACFU pinout, MC908AZ32ACFU application, or MC908AZ32ACFU equivalent, key selection criteria include CAN interface support, Flash endurance (100k erase/write cycles), low-voltage inhibit (LVI) threshold (2.7 V), 15-channel ADC with programmable gain, and compatibility with Freescale's MON monitor ROM for in-system programming and debug.

Technical Context

The MC908AZ32ACFU implements the enhanced M68HC08 CPU core with 16-bit index register, 16-bit stack pointer, and condition-code-based branching. Its System Integration Module (SIM) manages reset sources-including external RST, LVI, COP timeout, and break interrupts-and coordinates clock startup, stop/wait mode entry, and vectorized interrupt handling across 27 interrupt vectors.

The Clock Generator Module (CGM) integrates a crystal oscillator, PLL with programmable multiplication factor (×1 to ×32), and base clock selector supporting multiple clock sources (crystal, internal RC, or external). The MSCAN08 controller provides full CAN 2.0A/B compliance with message buffering, automatic retransmission, and error confinement-operating independently of CPU load via dedicated CAN RAM and registers.

Key Specifications

Pinout & Package

MC908AZ32ACFU is housed in a 64-pin Quad Flat Package (QFP) with 0.5 mm pitch, thermally enhanced for automotive under-hood environments. Pin assignments include dual power domains (VDD/VSS and VDDA/VSSA), dedicated CAN Tx/Rx pins (CANTx, CANRx), 15 ADC input channels mapped across Ports B/D, and 48 general-purpose I/O lines distributed across Ports A–H.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC908AZ32ACFU, MC9S12XDP512 offers scalable architecture for complex automotive software stacks, while S9KEAZN64AMLH reduces power consumption and simplifies certification but requires external CAN transceivers and protocol handling.

Availability

MC908AZ32ACFU is available at Aetrix Electronics and suitable for automotive body electronics, industrial CAN gateways, motor drive controllers, and smart sensor nodes requiring stable component supply across extended temperature ranges and long product lifecycles.

Supply support for MC908AZ32ACFU 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 since 2015) pioneered mixed-signal microcontrollers for automotive and industrial markets with robust qualification and long-term supply commitment.

The MC908AZ32ACFU belongs to the HCS08 family, designed specifically for cost-sensitive, high-reliability automotive applications requiring integrated CAN, analog sensing, and fail-safe operation in harsh environments.

FAQ

What is the maximum operating frequency of the MC908AZ32ACFU?

The MC908AZ32ACFU supports a maximum bus frequency of 40 MHz, achieved via its internal PLL clock generator with programmable multiplication factors (×1 to ×32) and selectable base clock sources. This allows flexible trade-offs between performance and power consumption. The PLL lock time is specified at ≤100 µs after power-up or wake-from-STOP, ensuring deterministic timing behavior critical for automotive real-time control loops. All timing parameters are validated across the full –40°C to +125°C temperature range.

Does the MC908AZ32ACFU include hardware CAN support?

Yes, the MC908AZ32ACFU integrates the MSCAN08 controller, a fully compliant CAN 2.0A/B module supporting bit rates up to 1 Mb/s, message filtering, automatic retransmission, and error confinement. It uses dedicated CAN RAM and registers independent of the main CPU bus, enabling concurrent CAN communication and application processing. The MC908AZ32ACFU requires an external CAN transceiver (e.g., TJA1042 or MC33886) connected to CANTx and CANRx pins for physical layer interfacing.

How is nonvolatile data storage handled on the MC908AZ32ACFU?

The MC908AZ32ACFU does not include dedicated EEPROM but provides 128 bytes of emulated EEPROM functionality using on-chip Flash memory. This is managed via Freescale's EEPROM emulation library, which implements wear-leveling and atomic write operations across designated Flash sectors. The MC908AZ32ACFU datasheet specifies Flash endurance at 100,000 erase/write cycles, and the emulation layer abstracts sector management to ensure data integrity across power-loss events and repeated updates.

What debug and programming interfaces does the MC908AZ32ACFU support?

The MC908AZ32ACFU supports in-circuit debugging and programming via its built-in Monitor ROM (MON), accessible through the SCI interface using standard UART signals (TxD/RxD). No external debugger hardware is required-flashing and breakpoint debugging can be performed using Freescale's P&E Micro BDM tools or custom host software. The Brake Module enables hardware-assisted break entry, preserving CPU register state and allowing single-step execution without modifying application code.

Is the MC908AZ32ACFU qualified for automotive applications?

Yes, the MC908AZ32ACFU is AEC-Q100 qualified for Grade 1 (–40°C to +125°C) operation and designed for automotive body electronics, chassis, and powertrain subsystems. It features integrated Low Voltage Inhibit (LVI) with 2.7 V reset threshold, COP watchdog with independent clock source, and robust ESD protection (±4 kV HBM). The MC908AZ32ACFU also meets automotive EMC requirements per ISO 11452 and CISPR 25, with layout guidelines documented in Freescale Application Note AN2221.