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.
This document contains information concerning standard and custom-ROM devices. Standard devices
are those with ROM or with EPROM replacing ROM (MC68HC711EA9). Custom-ROM devices have a
ROM array that is programmed at the factory to customer specifications. Where information in this document
refers to both the ROM and EPROM versions, the device is referred to as MC68HC(7)11EA9.
1.1 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)