General Description

Introduction

The MC68HC908QY4 is a member of the low-cost, high-performance M68HC08 Family of 8-bit microcontroller units (MCUs). The M68HC08 Family isa Complex Instruction Set Computer (CISC) with a Von Neumann architecture. All MCUs in the familyuse the enhanced M68HC08 central processor unit (CPU08) and are available with a variety of modules, memory sizes and types, and package types.

Features

Features include:

• High-performance M68HC08 CPU core

• Fully upward-compatible object code with M68HC05 Family

• 5-V and 3-V operating voltages (VDD)

• 8-MHz internal bus operation at 5 V, 4-MHz at 3 V

• Trimmable internal oscillator

– 3.2 MHz internal bus operation

– 8-bit trim capability allows 0.4% accuracy⁽¹⁾

– ± 25% untrimmed

• Auto wakeup from STOP capability

• Configuration (CONFIG) register for MCU configuration options, including:

– Low-voltage inhibit (LVI) trip point

• In-system FLASH programming

• FLASH security⁽²⁾

• On-chip in-application programmable FLASH memory (with internal program/erase voltage generation)

– MC68HC908QY4 and MC68HC908QT4 — 4096 bytes

– MC68HC908QY2, MC68HC908QY1, MC68HC908QT2, and MC68HC908QT1 — 1536 bytes

• 128 bytes of on-chip random-access memory (RAM)

• 2-channel, 16-bit timer interface module (TIM)

• 4-channel, 8-bit analog-to-digital converter (ADC) on MC68HC908QY2, MC68HC908QY4, MC68HC908QT2, and MC68HC908QT4

• 5 or 13 bidirectional input/output (I/O) lines and one input only:

– Six shared with keyboard interrupt function and ADC

– Two shared with timer channels

– One shared with external interrupt (IRQ)

– Eight extra I/O lines on 16-pin package only

– High current sink/source capability on all port pins

– Selectable pullups on all ports, selectable on an individual bit basis

– Three-state ability on all port pins

• 6-bit keyboard interrupt with wakeup feature (KBI)

• Low-voltage inhibit (LVI) module features:

– Software selectable trip point in CONFIG register

• System protection features:

– Computer operating properly (COP) watchdog

– Low-voltage detection with reset

– Illegal opcode detection with reset

– Illegal address detection with reset

• External asynchronous interrupt pin with internal pullup (IRQ) shared with general-purpose input pin

• Master asynchronous reset pin (RST) shared with general-purpose input/output (I/O) pin

• Power-on reset

• Internal pullups on IRQand RSTto reduce external components

• Memory mapped I/O registers

• Power saving stop and wait modes

• MC68HC908QY4, MC68HC908QY2, and MC68HC908QY1 are available in these packages:

– 16-pin plastic dual in-line package (PDIP)

– 16-pin small outline integrated circuit (SOIC) package

– 16-pin thin shrink small outline package (TSSOP)

• MC68HC908QT4, MC68HC908QT2, and MC68HC908QT1 are available in these packages:

– 8-pin PDIP

– 8-pin SOIC

– 8-pin dual flat no lead (DFN) package

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