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