Introduction
The MC68HC(7)05H12 HCMOS microcomputer is a member of the M68HC05 family. This 8 bit microcomputer unit (MCU) contains on-chip oscillator, CPU, RAM, (EP)ROM, monitor ROM, EEPROM, parallel I/O, one core timer, COP watchdog system, two 16-bit programmable timers, synchronous and asynchronous serial interface, a 4 channel A/D converter, and an 8 channel 8-bit PWM with on-chip power driver circuitry.

Features
• HC05 core
• 52 PLCC package
• 12032 bytes of user (EP)ROM + 240 bytes of monitor ROM + 16 bytes user vectors
• 256 bytes of RAM
• 256 bytes of EEPROM
• Multipurpose core timer, real time interrupt (RTI), COP watchdog timer
• Two 16-bit timers with two input captures and two output compares each
• Serial peripheral interface (SPI)
• Serial communications interface (SCI)
• 4 channel A/D converter (8-bit resolution)
• Keyboard interrupt for 8 I/O lines
• 8 channel 8-bit PWM system for control of H-bridge drivers
• 12 special power drivers to drive two major gauges and four minor gauges, with short circuit detection and slew rate limitation for reduced RFI (EMC)
• Power saving WAIT mode
• 2 selectable bus frequencies (slow mode)
• Low voltage reset (LVR) circuitry to hold the CPU in reset