Introduction
The Motorola MC68HC705P6A is an EPROM version of the MC68HC05P6 microcontroller. It is a low-cost combination of an M68HC05 Family microprocessor with a 4-channel, 8-bit analog-to-digital (A/D) converter, a 16-bit timer with output compare and input capture, a serial communications port (SIOP), and a computer operating properly (COP) watchdog timer. The HC05 CPU core contains 176 bytes of RAM, 4672 bytes of user EPROM, 239 bytes of bootloader ROM, and 21 input/output (I/O) pins (20 bidirectional, 1 input-only). This device is available in a 28-pin SOIC, PDIP, or windowed DIP package.

Features
• Low Cost
• HC05 Core
• 28-Pin SOIC, PDIP, or Windowed DIP Package
• 4672 Bytes of User EPROM (Including 48 Bytes of Page Zero EPROM and 16 Bytes of User Vectors)
• 239 Bytes of Bootloader ROM
• 176 Bytes of On-Chip RAM
• 4-Channel 8-Bit A/D Converter
• SIOP Serial Communications Port
• 16-Bit Timer with Output Compare and Input Capture
• 20 Bidirectional I/O Lines and 1 Input-Only line
• PC0 and PC1 High-Current Outputs
• Single-Chip, Bootloader, and Test Modes
• Power-Saving Stop, Halt, and Wait Modes
• Static EPROM Mask Option Register (MOR) Selectable Options:
   – COP Watchdog Timer Enable or Disable
   – Edge-Sensitive or Edge- and Level-Sensitive External Interrupt
   – SIOP Most Significant Bit (MSB) or Least Significant Bit (LSB) First
   – SIOP Clock Rates: OSC Divided by 8, 16, 32, or 64
   – Stop Instruction Mode, STOP or HALT
   – EPROM Security External Lockout
   – Programmable Keyscan (Pullups/Interrupts) on PA0–PA7