Introduction

The MC68HC908JL8 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 MC68HC908JL8 include the following:

? High-performance M68HC08 architecture,

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

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

? Maximum internal bus frequency:

– 8-MHz at 5V operating voltage

– 4-MHz at 3V operating voltage

? Oscillator options:

– Crystal or resonator

– RC oscillator

? 8,192 bytes user program FLASH memory with security1 feature

? 256 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; external clock input option on TIM2

? 13-channel, 8-bit analog-to-digital converter (ADC)

? Serial communications interface module (SCI)

? 26 general-purpose input/output (I/O) ports:

– 8 keyboard interrupt with internal pull-up

– 11 LED drivers (sink)

– 2 × 25mA open-drain I/O with pull-up

? Resident routines for in-circuit programming and EEPROM emulation

? System protection features:

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

– Optional low-voltage detection with reset and selectable trip points for 3V and 5V operation

– Illegal opcode detection with reset

– Illegal address detection with reset

? Master reset pin with internal pull-up and power-on reset

? IRQ with schmitt-trigger input and programmable pull-up

? 20-pin dual in-line package (PDIP), 20-pin small outline integrated package (SOIC), 28-pin PDIP, 28-pin SOIC, 32-pin shrink dual in line package (SDIP), and 32-pin low-profile quad flat pack (LQFP)

? Specific features of the MC68HC908JL8 in 28-pin packages are:

– 23 general-purpose I/Os only

– 7 keyboard interrupt with internal pull-up

– 10 LED drivers (sink)

– 12-channel ADC

– Timer I/O pins on TIM1 only

? Specific features of the MC68HC908JL8 in 20-pin packages are:

– 15 general-purpose I/Os only

– 1 keyboard interrupt with internal pull-up

– 4 LED drivers (sink)

– 10-channel ADC

– Timer I/O pins on TIM1 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