NXP Semiconductors MC68908GZ16CFJE

Overview

MC68908GZ16CFJE from Freescale Semiconductor is an 8-bit HCS08-core microcontroller featuring 16 KB on-chip Flash memory, 512 B RAM, integrated 10-bit ADC with 8 input channels, dual serial interfaces (ESCI and SPI), and a CAN 2.0A/B controller. It operates at up to 8 MHz bus frequency with internal PLL clock generation and supports low-power wait/stop modes for battery-sensitive applications such as automotive body control modules and industrial sensor nodes.

For engineers reviewing the MC68908GZ16CFJE datasheet, MC68908GZ16CFJE pinout, MC68908GZ16CFJE application, or MC68908GZ16CFJE equivalent, key selection criteria include its integrated MSCAN08 controller, 40-pin LQFP package with dedicated CAN TX/RX pins, Flash programmability in-system, and support for both 5 V and 3.3 V operation with configurable I/O drive strength.

Technical Context

The MC68908GZ16CFJE implements the HCS08 CPU core with enhanced addressing modes and a 16-level hardware stack. Its Clock Generator Module includes a crystal oscillator input, PLL with programmable multiplier (×1 to ×32), and selectable base clock sources (internal RC, external crystal, or external clock).

The integrated MSCAN08 controller supports CAN 2.0A/B protocol with message buffering, automatic retransmission, and error confinement. The ESCI module provides full-duplex asynchronous communication with programmable baud rates, while the SPI supports master/slave operation with 4-wire interface and DMA-ready data transfer.

Key Specifications

Pinout & Package

MC68908GZ16CFJE is housed in a 40-pin LQFP (7 mm × 7 mm, 0.8 mm pitch) package with exposed thermal pad. Pin assignments follow Freescale's standardized HCS08 GZ-series layout, including dedicated CAN TX/RX, ESCI TX/RX, SPI SCK/MOSI/MISO/SS, and ADC input channels mapped to Port B pins.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC9S08DZ128 and MC9S12XEP100, the MC68908GZ16CFJE delivers optimal cost-performance balance for entry-level CAN nodes where deterministic 8-bit control, compact code size, and minimal BOM count are prioritized over raw throughput or protocol extension.

Availability

MC68908GZ16CFJE is available at Aetrix Electronics and suitable for automotive body electronics, industrial sensor networks, home appliance motor control, and portable medical devices requiring stable component supply across long production lifecycles.

Supply support for MC68908GZ16CFJE 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 HCS08 architecture for cost-sensitive, low-power embedded control applications.

The MC68908GZ16CFJE belongs to the HCS08 GZ-series, designed specifically for automotive and industrial CAN-based distributed control systems requiring robust communication, analog sensing, and field-upgradable firmware in constrained form factors.

FAQ

What is the maximum operating frequency of the MC68908GZ16CFJE?

The MC68908GZ16CFJE supports a maximum bus frequency of 8 MHz. This is achieved using the internal PLL with programmable multiplication factor (×1 to ×32) driven by an external crystal (1–8 MHz) or internal RC oscillator. The PLL allows flexible clock scaling while maintaining stability across voltage and temperature variations, and the MC68908GZ16CFJE's timing specifications are fully characterized up to this 8 MHz limit.

Does the MC68908GZ16CFJE support CAN FD?

No, the MC68908GZ16CFJE integrates the MSCAN08 controller, which complies strictly with CAN 2.0A/B (ISO 11898-1) and does not support CAN FD features such as variable bit rate, extended data length (up to 64 bytes), or CRC enhancements. For CAN FD capability, designers should consider later-generation NXP S32K or S12Z devices - the MC68908GZ16CFJE remains optimized for legacy and cost-sensitive CAN 2.0 networks.

How many ADC channels does the MC68908GZ16CFJE have, and what is their resolution?

The MC68908GZ16CFJE features a 10-bit successive-approximation ADC with 8 analog input channels (AD0–AD7), mapped to Port B pins PTB0 through PTB7. It supports single-ended conversion only, with programmable sample time and left/right-justified result formatting. The ADC is specified for ±1 LSB integral nonlinearity and operates across the full 2.7–5.5 V supply range, with dedicated VDDAD/VSSAD pins enabling noise-isolated analog measurements.

Can the MC68908GZ16CFJE operate from a 3.3 V supply?

Yes, the MC68908GZ16CFJE is fully specified for 3.3 V operation (±10 %), with all digital I/Os 5 V tolerant when configured as inputs. Its internal voltage regulator generates a stable 3.3 V analog supply (VDDA) for the ADC and PLL circuits, eliminating the need for an external LDO in 3.3 V system designs. Electrical characteristics including propagation delay, ADC accuracy, and CAN transceiver interface compatibility are validated across the 2.7–5.5 V range, making the MC68908GZ16CFJE suitable for mixed-voltage architectures.

What debug and programming interfaces does the MC68908GZ16CFJE support?

The MC68908GZ16CFJE supports background debug mode (BDM) via a dedicated 6-pin interface (BKGD, RESET, VDD, VSS, VDDA, VSSA), enabling non-intrusive in-circuit debugging, flash programming, and real-time register inspection. It does not support JTAG or SWD. Programming is performed using Freescale's BDM-compatible tools (e.g., DEMO9S08GB60 evaluation board with USB-BDM interface), and the MC68908GZ16CFJE's Flash memory supports in-application programming (IAP) for field firmware updates without external programmers.