Introduction
The MC68HC11A8, MC68HC11A1, and MC68HC11A0 high-performance microcontroller units (MCUs) are based on the M68HC11 Family. These high speed, low power consumption chips have multiplexed buses and a fully static design. The chips can operate at frequencies from 3 MHz to dc. The three MCUs are created from the same masks; the only differences are the value stored in the CONFIG register, and whether or not the ROM or EEPROM is tested and guaranteed.

Features
• M68HC11 CPU
• Power Saving STOP and WAIT Modes
• 8 Kbytes ROM
• 512 Bytes of On-Chip EEPROM
• 256 Bytes of On-Chip RAM (All Saved During Standby)
• 16-Bit Timer System
    — 3 Input Capture Channels
    — 5 Output Compare Channels
• 8-Bit Pulse Accumulator
• Real-Time Interrupt Circuit
• Computer Operating Properly (COP) Watchdog System
• Synchronous Serial Peripheral Interface (SPI)
• Asynchronous Nonreturn to Zero (NRZ) Serial Communications Interface (SCI)
• 8-Channel, 8-Bit Analog-to-Digital (A/D) Converter
• 38 General-Purpose Input/Output (I/O) Pins
    — 15 Bidirectional I/O Pins
    — 11 Input-Only Pins and 12 Output-Only Pins (Eight Output-Only Pins in 48-Pin Package)
• Available in 48-Pin Dual In-Line Package (DIP) or 52-Pin Plastic Leaded Chip Carrier (PLCC)