NXP Semiconductors MC908LJ12CFBE

Overview

MC908LJ12CFBE from Freescale Semiconductor is an 8-bit HCS08-core microcontroller with 12 KB on-chip FLASH, 512 B RAM, integrated LCD driver (up to 18 segments), real-time clock (RTC), IRSCI interface, and SPI/SCI peripherals. It operates at up to 8 MHz bus frequency, supports 2.7–5.5 V supply, and targets low-power embedded control in portable instrumentation and consumer displays.

For engineers reviewing the MC908LJ12CFBE datasheet, MC908LJ12CFBE pinout, MC908LJ12CFBE application, or MC908LJ12CFBE equivalent, this page delivers verified technical context, validated pin functions, confirmed peripheral capabilities (RTC, IRSCI, LCD), and direct alternative options for migration or second-sourcing in cost-sensitive, battery-powered MCU designs.

Technical Context

The MC908LJ12CFBE implements the HCS08 CPU core with enhanced addressing modes and a 16-level hardware stack. Its Clock Generator Module (CGM) integrates a PLL for flexible clock synthesis from internal RC or external crystal sources, enabling precise bus timing across voltage and temperature ranges.

System integration includes a System Integration Module (SIM) managing reset sources (POR, LVI, COP), interrupt prioritization, and low-power modes (Wait/Stop). The Real Time Clock (RTC) provides calendar, alarm, and chronograph functions with independent 32.768 kHz oscillator support - all accessible without CPU intervention.

Key Specifications

Pinout & Package

MC908LJ12CFBE is housed in a 52-pin QFP (Quad Flat Package) with 0.65 mm pitch, measuring 10 mm × 10 mm. Pin assignments are defined per Section 1.5 (Pin Assignments) and Section 1.6 (Pin Functions) of Freescale Document MC68HC908LJ12/D Rev. 2.1.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MC908LJ12CFBE, MC908LJ12CPBE offers identical functionality in RoHS-compliant packaging, while MC9RS08LA8 sacrifices RTC and IRSCI for lower cost and power - making it unsuitable for time-aware or IR-controlled applications unless redesigned.

Availability

MC908LJ12CFBE is available at Aetrix Electronics and suitable for portable medical devices, industrial panel meters, smart home thermostats, and consumer appliance UIs requiring stable component supply and long-term obsolescence management.

Supply support for MC908LJ12CFBE 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) is a global leader in embedded processing solutions, delivering microcontrollers, analog, and connectivity products for automotive, industrial, and consumer markets.

The MC908LJ12CFBE belongs to the HCS08 family, designed specifically for cost-sensitive, low-power embedded control applications requiring integrated LCD, RTC, and IR interfaces - targeting portable instrumentation and human-interface devices.

FAQ

What is the maximum operating frequency of the MC908LJ12CFBE?

The MC908LJ12CFBE supports a maximum bus frequency of 8 MHz, achieved via its internal Clock Generator Module (CGM) with PLL. This frequency is sustained across the full 2.7–5.5 V supply range and commercial temperature grade (–40°C to +85°C), as specified in Section 23 (Electrical Specifications) of the MC68HC908LJ12/D Rev. 2.1 datasheet. The MC908LJ12CFBE does not require external clock multiplication circuitry to reach this rate.

Does the MC908LJ12CFBE include a hardware real-time clock?

Yes, the MC908LJ12CFBE integrates a full-featured Real Time Clock (RTC) module with calendar (year/month/day/hour/min/sec), alarm, and chronograph functions. It accepts a dedicated 32.768 kHz crystal on OSC1/OSC2 and continues operation in Stop mode with typical current draw below 1 µA. This RTC is documented in Section 12 of the MC68HC908LJ12/D Rev. 2.1 technical data manual.

Can the MC908LJ12CFBE drive a multiplexed LCD display?

Yes, the MC908LJ12CFBE's integrated LCD driver supports static, 2-mux, 3-mux, and 4-mux configurations across its BP0–BP2 backplane and FP0/BP3, FP1–FP18 frontplane pins. Software controls bias voltage, duty cycle, and frame frequency - enabling direct drive of common segment-based displays without external bias generators or controllers. Details are in Section 16 of the MC68HC908LJ12/D Rev. 2.1 datasheet.

What communication interfaces are available on the MC908LJ12CFBE?

The MC908LJ12CFBE provides three serial interfaces: an Infrared Serial Communications Interface (IRSCI) supporting NEC/RC-5 protocols on PTB0/PTB1, a standard Serial Peripheral Interface (SPI) module, and a Serial Communications Interface (SCI) sharing pins with IRSCI. These are fully documented in Sections 13, 14, and 13 (SCI subsection) of the MC68HC908LJ12/D Rev. 2.1 technical data manual.

Is the MC908LJ12CFBE pin-compatible with other HCS08 family members?

No, the MC908LJ12CFBE is not pin-compatible with other HCS08 MCUs such as the MC908JB12 or MC908AP64. Its 52-pin QFP package and specific peripheral mapping (e.g., LCD pins FP0/BP3, BP0–BP2) are unique to the LJ12 series. Pin assignments are fixed per Section 1.5 of the MC68HC908LJ12/D Rev. 2.1 datasheet and must be verified individually for any migration effort involving the MC908LJ12CFBE.