NXP Semiconductors MC68HC908JL8CSPE

Overview

MC68HC908JL8CSPE from NXP (formerly Freescale) is an 8-bit HCS08-core microcontroller with 8 KB on-chip Flash, 512 B RAM, and integrated peripherals including SCI, TIM, ADC, KBI, and COP watchdog. It operates at up to 8 MHz bus frequency, supports 3.0–5.5 V supply, and targets low-cost embedded control in industrial sensors and appliance subsystems.

For engineers reviewing the MC68HC908JL8CSPE datasheet, MC68HC908JL8CSPE pinout, MC68HC908JL8CSPE application, or MC68HC908JL8CSPE equivalent, key selection criteria include Flash endurance (10k erase/write cycles), 8-channel 8-bit ADC with 25 μs conversion time, SCI asynchronous serial interface, and support for Wait/Stop low-power modes with wake-on-IRQ/KBI.

Technical Context

The MC68HC908JL8CSPE implements the HCS08 CPU core with 16-bit address space, indexed addressing, and 72-instruction set optimized for compact code. Its System Integration Module (SIM) provides clock generation from internal RC or external crystal oscillator, configurable reset sources (POR, LVI, COP), and interrupt vectoring across 16 priority levels.

Peripheral integration includes a 16-bit Timer Interface Module (TIM) with input capture, output compare, and PWM; an 8-channel 8-bit Analog-to-Digital Converter (ADC) with software-triggered conversions; and a Serial Communications Interface (SCI) supporting full-duplex asynchronous communication at baud rates up to 115.2 kbps with framing error detection.

Key Specifications

Pinout & Package

MC68HC908JL8CSPE is housed in a 28-pin SOIC (Small Outline Integrated Circuit) package with 24 I/O pins, 2 power pins (VDD, VSS), and 2 oscillator pins (OSC1, OSC2). Pin functions are defined per the Rev. 3.1 datasheet Section 1.4 and Table 1-1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC68HC908JL8CSPE, MC9RS08KA8CP trades peripheral integration for lower gate count and cost, while MC9S08QG8CDT offers identical HCS08 functionality in a smaller footprint but sacrifices I/O count and KBI capability - making MC68HC908JL8CSPE optimal for full-featured, cost-sensitive industrial UI and control nodes.

Availability

MC68HC908JL8CSPE is available at Aetrix Electronics and suitable for industrial sensor nodes, home appliance control panels, and motor speed regulators requiring stable component supply and long-term manufacturing continuity.

Supply support for MC68HC908JL8CSPE 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 is a global semiconductor leader focused on secure connectivity solutions for automotive, industrial, and IoT applications.

The MC68HC908JL8CSPE belongs to the legacy HCS08 microcontroller family designed for cost-effective, low-power embedded control in appliances, industrial equipment, and consumer electronics - emphasizing integration, reliability, and toolchain maturity.

FAQ

What is the maximum bus frequency supported by the MC68HC908JL8CSPE?

The MC68HC908JL8CSPE supports a maximum bus frequency of 8 MHz, derived from its internal oscillator or external crystal source. This frequency determines instruction execution speed and peripheral timing - for example, SCI baud rate generation and ADC conversion intervals scale directly with bus clock. The device maintains timing integrity across its full operating voltage range (3.0–5.5 V) and temperature range (–40 °C to +85 °C).

Does the MC68HC908JL8CSPE include a hardware debug interface?

The MC68HC908JL8CSPE does not feature a dedicated JTAG or SWD debug interface. Instead, it relies on its built-in Monitor ROM (MON) accessed via the SCI interface for in-circuit programming and basic debugging. This MON-based method supports flash programming, register inspection, and memory read/write operations - sufficient for production programming and field updates, though lacking real-time breakpoint or step-through capabilities of full debug interfaces.

How many I/O pins does the MC68HC908JL8CSPE provide, and which ports support interrupt-on-change?

The MC68HC908JL8CSPE provides 24 general-purpose I/O pins across Ports A (8 pins), D (8 pins), and E (2 pins), plus dedicated function pins (OSC1, OSC2, RxD, TxD, IRQ, RESET). Port A pins (PTA0–PTA7) support Keyboard Interrupt (KBI) - a dedicated interrupt-on-change module with configurable edge sensitivity and internal debounce - enabling low-power wake-up from Stop mode on keypad activity without CPU polling.

Can the MC68HC908JL8CSPE operate from a 3.3 V supply, and what are the implications for oscillator stability?

Yes, the MC68HC908JL8CSPE operates across 3.0–5.5 V, including standard 3.3 V systems. At 3.3 V, the internal RC oscillator remains functional but exhibits higher frequency tolerance (±5% typical) versus ±1% with an external 3.3 V–rated crystal on OSC1/OSC2. For timing-critical applications like SCI communication or PWM generation, use of an external crystal is recommended to maintain baud rate accuracy and consistent PWM period.

What is the Flash endurance specification for the MC68HC908JL8CSPE, and how is wear leveling managed?

The MC68HC908JL8CSPE specifies 10,000 erase/write cycles for its 8 KB on-chip Flash memory. It does not include hardware wear leveling; endurance management must be implemented in firmware - for example, by rotating write locations in a circular buffer or segregating frequently updated parameters into dedicated Flash sectors. The Flash Block Protect Register allows locking critical bootloader or calibration regions to prevent accidental overwrite during field updates.