Introduction

The MC68HC908LJ12 is a member of the low-cost, high-performance M68HC08 Family of 8-bit microcontroller units (MCUs). The M68HC08 Family is based on the customer-specified integrated circuit (CSIC) design strategy. All MCUs in the family use the enhanced M68HC08 central processor unit (CPU08) and are available with a variety of modules, memory sizes and types, and package types.

Features

Features of the MC68HC908LJ12 include the following:

? High-performance M68HC08 architecture

? Fully upward-compatible object code with M6805, M146805, and M68HC05 Families

? Maximum internal bus frequency:

– 8-MHz at 5V operating voltage

– 4-MHz at 3.3V operating voltage

? 32-kHz crystal oscillator clock input with 32MHz internal phaselock-loop

? Optional continuous crystal oscillator operation in stop mode

? 12k-bytes user program FLASH memory with security1 feature

? 512 bytes of on-chip RAM

? Two 16-bit, 2-channel timer interface modules (TIM1 and TIM2) with selectable input capture, output compare, and PWM capability on each channel

? Real time clock (RTC) with clock, calendar, alarm, and chronograph functions. Selectable periodic interrupt requests for seconds, minutes, hours, days, 2-Hz, 4-Hz, and 100-Hz

? Serial communications interface module (SCI) with infrared (IR) encoder/decoder

? Serial peripheral interface module (SPI)

? IRQ external interrupt pin with integrated pullup

? 8-bit keyboard wakeup port with programmable pullup

? 32 general-purpose input/output (I/O) pins:

– High current 8-mA sink capability on PTB2–PTB5

– High current 20-mA sink capability on PTB0–PTB1

? 4/3 backplanes and static with maximum 27 frontplanes liquid crystal display (LCD) driver

? 6-channel, 10-bit successive approximation analog-to-digital converter (ADC)

? Resident routines for in-circuit programming and EEPROM emulation

? Low-power design (fully static with stop and wait modes)

? Master reset pin (with integrated pullup) and power-on reset

? Spike filter protection for EMC performance enhancement

? System protection features

– Optional computer operating properly (COP) reset, driven by internal 64-kHz RC oscillator

– Low-voltage detection with optional reset or interrupt

– Illegal opcode detection with reset

– Illegal address detection with reset

? 64-pin quad flat pack (QFP), 64-pin low-profile quad flat pack (LQFP), 52-pin low-profile quad flat pack (LQFP), and die form

? Specific features of the MC68HC908LJ12 in 52-pin LQFP are:

– 20 general-purpose I/Os only

– High current 8-mA sink capability on PTB2–PTB3 only

– 4-bit keyboard wakeup port with programmable pullup

– No serial peripheral interface module (SPI)

– No TIM2 input capture/output compare pins

– 4-channel analog-to-digital converter only

Features of the CPU08 include the following:

? Enhanced HC05 programming model

? Extensive loop control functions

? 16 addressing modes (eight more than the HC05)

? 16-bit Index register and stack pointer

? Memory-to-memory data transfers

? Fast 8 × 8 multiply instruction

? Fast 16/8 divide instruction

? Binary-coded decimal (BCD) instructions

? Optimization for controller applications

? Efficient C language support