NXP Semiconductors MC68HC908LJ12CFU

Overview

MC68HC908LJ12CFU from NXP (formerly Freescale) is an 8-bit HCS08 microcontroller with 12 KB on-chip FLASH, 512 B RAM, integrated LCD driver (18 frontplane/3 backplane), real-time clock (RTC), IRSCI interface, and SPI. It operates at up to 8 MHz bus frequency and supports low-power stop/wait modes for battery-powered instrumentation and industrial control panels.

For engineers reviewing the MC68HC908LJ12CFU datasheet, MC68HC908LJ12CFU pinout, MC68HC908LJ12CFU application, or MC68HC908LJ12CFU equivalent, key selection criteria include its integrated RTC accuracy (±1 ppm typical drift), LCD drive capability (up to 54 segments), IRSCI modulation compliance with IrDA 1.0 physical layer, and FLASH endurance (100K erase/write cycles).

Technical Context

The MC68HC908LJ12CFU implements the HCS08 CPU core with 16-bit index register, 8-bit accumulator, and 16-bit program counter. Its Clock Generator Module (CGM) integrates a PLL with programmable multiplier (×1 to ×32) and reference divider, enabling precise bus clock synthesis from crystal or internal RC sources.

The System Integration Module (SIM) provides centralized reset management-including POR, LVI, COP, and illegal opcode detection-and coordinates low-power mode entry/exit across TIM, RTC, IRSCI, and SPI peripherals. The IRSCI module combines infrared encoder/decoder logic with standard SCI framing, supporting both asynchronous serial communication and 38 kHz carrier-modulated IR data transmission.

Key Specifications

Pinout & Package

MC68HC908LJ12CFU is housed in a 64-pin QFP (Quad Flat Package) with 0.5 mm pitch, compliant with JEDEC MS-026. Pin assignments are defined per Section 1.5 (Pin Assignments) and Section 1.6 (Pin Functions) of the Rev. 2.1 Technical Data document.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC9RS08LA8CFU, MC68HC908LJ12CFU delivers full RTC and IRSCI functionality at the expense of higher active current; versus MC9S08LG32CFU, it trades CAN and memory capacity for lower unit cost and identical LCD/IR feature set in compact 64-QFP footprint.

Availability

MC68HC908LJ12CFU is available at Aetrix Electronics and suitable for industrial control panels, portable medical instruments, energy meter displays, and smart appliance remote interfaces requiring stable component supply and long-term lifecycle support.

Supply support for MC68HC908LJ12CFU 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 company specializing in secure connectivity solutions for automotive, industrial, and IoT applications.

The MC68HC908LJ12CFU belongs to the HCS08 microcontroller family designed for cost-effective, low-power embedded systems requiring integrated LCD, RTC, and infrared communication-targeting instrumentation, home appliances, and building automation.

FAQ

What is the maximum bus frequency supported by the MC68HC908LJ12CFU?

The MC68HC908LJ12CFU supports a maximum bus frequency of 8 MHz, achieved through its integrated Clock Generator Module (CGM) with PLL multiplication. This frequency is configurable via the PLL multiplier select registers and remains stable across voltage and temperature ranges specified in the electrical characteristics section of the datasheet.

Does the MC68HC908LJ12CFU include hardware support for infrared communication?

Yes, the MC68HC908LJ12CFU integrates an Infrared Serial Communications Interface (IRSCI) module compliant with IrDA 1.0 physical layer specifications. It provides dedicated hardware for 38 kHz carrier modulation and demodulation, eliminating the need for external IR transceiver ICs in remote control receiver applications.

Can the MC68HC908LJ12CFU drive a multiplexed LCD display?

Yes, the MC68HC908LJ12CFU's LCD driver supports static and multiplexed configurations up to 1/3 bias and 1/4 duty cycle. With 18 frontplane and 3 backplane outputs, it can drive up to 54 segments-enabling direct connection to common industrial LCD modules without external bias generation circuitry.

What type of reset sources are available on the MC68HC908LJ12CFU?

The MC68HC908LJ12CFU features multiple reset sources: external RST pin, Power-On Reset (POR), Low-Voltage Inhibit (LVI), Computer Operating Properly (COP) watchdog timeout, illegal opcode detection, illegal address access, and Monitor Mode Entry (MODRST). All are managed centrally by the System Integration Module (SIM).

Is there on-chip debug or programming support for the MC68HC908LJ12CFU?

Yes, the MC68HC908LJ12CFU includes a 1 KB Monitor ROM (MON) that provides flash programming, memory verification, and bootloader functions. It supports in-system programming via the IRSCI or standard SCI interface using a break signal to enter monitor mode without requiring external debug hardware.