General Description

Introduction

The Motorola MC68HC05P18A is a low-cost microcontroller with:

? 4-channel, 8-bit analog-to-digital (A/D) converter

? 16-bit timer with output compare and input capture

? Serial communications port (SIOP)

? Computer operating properly (COP) watchdog timer

The HC05 central processor unit (CPU) core contains:

? 192 bytes of random-access memory (RAM)

? 8064 bytes of user read-only memory (ROM)

? 128 bytes of electrically erasable programmable read-only memory (EEPROM)

? 21 input/output (I/O) pins (20 bidirectional, 1 input-only)

This device is available in:

? 28-pin plastic dual in-line package (PDIP)

? 28 pin small-outline integrated circuit package (SOIC)

A functional block diagram of the MC68HC05P18A is shown in Figure 1-1.

Features

Features of the MC68HC05P18A include:

? Low-cost, HC05 core running at 2-MHz bus speed, or the 4-MHz high-speed option

? 28-pin DIP or SOIC package

? On-chip crystal/ceramic resonator

? 8064 bytes of user ROM including:

– 48 bytes of page zero ROM

– 16 bytes of user vectors

? 192 bytes of on-chip RAM

? 128 bytes of EEPROM

? Low-voltage reset (LVR)

? Four-channel, 8-bit A/D converter

? Serial communications port

? COP watchdog timer with active pull down on RESET

? 16-bit timer with output compare and input capture

? Edge- and level-sensitive interrupt or edge-sensitive only (mask option)

? 20 bidirectional I/O lines and 1 input-only line

? Individually mask selectable pullups/interrupts on port A pins

? High current sink and source on two I/O pins, PC0 and PC1

? Power-saving stop mode and wait mode instructions and stop conversion to halt mode (mask option)

? Mask option for clock output pin