Introduction

The MC68HC11EA9 and MC68HC711EA9 microcontroller units (MCUs) are high-performance members of the M68HC11 family of MCUs. The MC68HC(7)11EA9 MCUs have a multiplexed external address and data bus and are characterized by high speed and low power consumption. Their fully static design allows operation at frequencies from 3 MHz to dc. The addition of a phase-locked loop (PLL) frequency synthesizer to the timer circuitry further enhances low-power operation and allows the use of lower frequency crystals while maintaining a clock speed of up to 3 MHz.

Features

• M68HC11 CPU

• 512 Bytes RAM (Data Retained During Standby, by use of VSTBY)

• 12 Kbytes Mask-Programmed ROM or EPROM

• 512 Bytes Electrically Erasable Programmable ROM (EEPROM)

• PROG Mode Allows Use of Standard EPROM Programmer (27C256 Footprint)

• Multiplexed Address and Data Buses Reduce Pin Count

• Enhanced 16-Bit Timer with Four-Stage Programmable Prescaler

— Three Input Capture (IC) Channels

— Four Output Compare (OC) Channels

— One Additional Channel, Selectable as Fourth IC or Fifth OC

• 8-Bit Pulse Accumulator

• Phase-Locked Loop (PLL) Frequency Synthesizer for Reduced Power Consumption

• Power Saving STOP and WAIT Modes

• Real-Time Interrupt Circuit

• Computer Operating Properly (COP) Watchdog Timer

• Clock Monitor Circuit

• Enhanced Asynchronous Nonreturn to Zero (NRZ) Serial Communications Interface (SCI)

• Eight-Channel 8-Bit Analog-to-Digital (A/D) Converter

• Five Input/Output (I/O) Ports (34 Pins)

— Four Bidirectional I/O Ports (26 Pins)

— One Fixed Input-Only Port (8 Pins)

• Two Alternate, Fixed Input-Only Pins (XIRQ pin/XPIN bit and IRQ pin/IPIN bit)

• Available in 52-Pin Plastic Leaded Chip Carrier (PLCC), 52-Pin Windowed Ceramic Leaded Chip

Carrier (CLCC), and 56-Pin SDIP (0.070” Lead Spacing)