NXP Semiconductors MC68HC908GR16CFJ

Overview

MC68HC908GR16CFJ from Freescale Semiconductor is an 8-bit HCS08-core microcontroller with 16 KB on-chip Flash memory, 512 B RAM, and integrated peripherals including ADC, SPI, ESCI, TIM, KBI, and CGM with PLL-based clock synthesis. It operates at up to 8 MHz bus frequency, supports 5 V operation, and targets embedded control in industrial sensors, motor drives, and appliance subsystems.

For engineers reviewing the MC68HC908GR16CFJ datasheet, MC68HC908GR16CFJ pinout, MC68HC908GR16CFJ application, or MC68HC908GR16CFJ equivalent, key selection criteria include its 40-pin SOIC-40 package, 8-channel 10-bit ADC with internal reference, PLL-configurable clock generation, COP watchdog, and low-power Wait/Stop modes with wake-on-KBI or IRQ.

Technical Context

The MC68HC908GR16CFJ implements the CPU08 core with 16-bit address space, 8-level hardware stack, and instruction set optimized for real-time control. Its Clock Generator Module integrates a crystal oscillator, PLL with programmable multiplier (×1 to ×32), and base clock selector enabling flexible system clock derivation from external crystals or internal RC sources.

The Enhanced Serial Communications Interface (ESCI) supports asynchronous full-duplex UART operation with selectable baud rates, LIN-compatible framing, and CGMXCLK or BUS CLOCK as timing source. The 10-bit ADC features sample-and-hold, programmable conversion triggers (software, timer, or ESCI), and left/right-justified 16-bit result registers.

Key Specifications

Pinout & Package

MC68HC908GR16CFJ is housed in a 40-pin SOIC (Small Outline Integrated Circuit) package with 0.75 mm lead pitch, compliant with JEDEC MS-013AC. Pin assignments are defined per Figure 1-4 and Table 1-2 of Rev. 5.0 datasheet.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC9RS08KA8CFD and MC9S08QG8CDT, the MC68HC908GR16CFJ provides higher Flash density, full KBI support for UI, and PLL flexibility for precision timing - making it optimal for feature-rich 5 V embedded controllers requiring field-upgradable firmware and multi-sensor interfacing.

Availability

MC68HC908GR16CFJ is available at Aetrix Electronics and suitable for industrial sensor nodes, appliance motor control subsystems, and smart power outlets requiring stable component supply across extended production lifecycles.

Supply support for MC68HC908GR16CFJ 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 8-bit MCU architectures for cost-sensitive, high-reliability embedded applications across automotive, industrial, and consumer markets.

The MC68HC908GR16CFJ belongs to the HCS08 family, designed specifically for 5 V embedded control systems demanding integrated analog peripherals, robust clocking, and low-power operation without external timing components.

FAQ

What is the maximum operating frequency of the MC68HC908GR16CFJ?

The MC68HC908GR16CFJ achieves a maximum bus frequency of 8 MHz, derived from its internal PLL circuit. This frequency is programmable via the PLL Multiplier Select Registers and requires configuration of the CGM module using the CGMXCLK output as the system clock source. The PLL supports multiplication factors from ×1 to ×32, allowing precise clock synthesis from low-frequency crystals.

Does the MC68HC908GR16CFJ support in-system programming?

Yes, the MC68HC908GR16CFJ supports in-system programming via its on-chip Flash memory. The Flash Control Register enables page erase, mass erase, and byte/word programming operations without removing the device from the target board. Programming requires the BGND (background debug) pin and compatible Freescale BDM tools, and is fully supported in the MC68HC908GR16CFJ's ROM-resident bootloader.

What ADC reference voltage does the MC68HC908GR16CFJ use?

The MC68HC908GR16CFJ uses an internal 2.5 V bandgap reference for its 10-bit ADC, accessible via the VREFH and VREFL pins. This eliminates the need for an external reference in most applications. The ADC also supports external reference configurations by connecting VREFH to an external source while grounding VREFL, as specified in Section 3.7 of the Rev. 5.0 datasheet.

Can the MC68HC908GR16CFJ operate in low-power Stop mode with wake-up capability?

Yes, the MC68HC908GR16CFJ supports Stop mode with wake-up triggered by IRQ, KBI, or reset events. In Stop mode, the CPU, Flash, and most peripherals are disabled, reducing current consumption to approximately 1 µA. Wake-up latency is under 4 µs, and the device resumes execution from the point of interruption - a critical feature for battery-powered MC68HC908GR16CFJ deployments.

Is the MC68HC908GR16CFJ pin-compatible with other HCS08 family members?

No, the MC68HC908GR16CFJ is not pin-compatible with other HCS08 devices due to its unique 40-pin SOIC footprint and specific peripheral mapping (e.g., KBI on Port A, ESCI on Port E). While functional similarities exist across the family, PCB layout must be designed specifically for the MC68HC908GR16CFJ's pinout as documented in Section 1.4 of the Rev. 5.0 datasheet.