Introduction

The MC68HC908MR24 is a member of the low-cost, high-performance M68HC08 Family of 8-bit microcontroller units (MCUs). The M68HC08 Family is based on the customer-specified integrated circuit (CSIC) design strategy. All MCUs in the family use the enhanced M68HC08 central processor unit (CPU08) and are available with a variety of modules, memory sizes and types, and package types.

Features

Features of the MC68HC908MR24 include:

• High-performance M68HC08 architecture

• Fully upward-compatible object code with M6805, M146805, and M68HC05 Families

• 8-MHz internal bus frequency

• 24 Kbytes of on-chip electrically erasable in-circuit programmable read-only memory (FLASH)

• On-chip programming firmware for use with host personal computer

• FLASH data security1

• 768 bytes of on-chip random-access memory (RAM)

• 12-bit, 6-channel center-aligned or edge-aligned pulse-width modulator (PWMMC)

• Serial peripheral interface module (SPI)

• Serial communications interface module (SCI)

• 16-bit, 4-channel timer interface module (TIMA)

• 16-bit, 2-channel timer interface module (TIMB)

• Clock generator module (CGM)

• Low-voltage inhibit (LVI) module with software selectable trip points

• 10-bit, 10-channel analog-to-digital converter (ADC)

• System protection features:

– Optional computer operating properly (COP) reset

– Low-voltage detection with optional reset

– Illegal opcode detection with optional reset

– Illegal address detection with optional reset

– Fault detection with optional PWM disabling

• 64-pin plastic quad flat pack (QFP)

• 56-pin shrink dual in-line package (SDIP)

• Low-power design (fully static with wait mode)

• Master reset pin (RST) and power-on reset (POR)

Features of the CPU08 include:

• Enhanced HC05 programming model

• Extensive loop control functions

• 16 addressing modes (eight more than the HC05)

• 16-bit index register and stack pointer

• Memory-to-memory data transfers

• Fast 8 × 8 multiply instruction

• Fast 16/8 divide instruction

• Binary-coded decimal (BCD) instructions

• Optimization for controller applications

• C language support