MC68HC908GR8A_07 Datasheet, PDF (19/260 Pages) Freescale Semiconductor, Inc – Microcontrollers

Chapter 1
General Description
1.1 Introduction
The MC68HC908GR8A is a member of the low-cost, high-performance M68HC08 Family of 8-bit
microcontroller units (MCUs). 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.
This document also describes the MC68HC908GR4A. The MC68HC908GR4A is a device identical to the
MC68HC908GR8A except that it has less FLASH memory. Only when there are differences from the
MC68HC908GR8A is the MC68HC908GR4A specifically mentioned in the text.
1.2 Features
For convenience, features have been organized to reflect:
• Standard features
• Features of the CPU08
1.2.1 Standard Features
Features include:
• High-performance M68HC08 architecture optimized for C-compilers
• Fully upward-compatible object code with M6805, M146805, and M68HC05 Families
• 8-MHz internal bus frequency
• Clock generation module supporting 1-MHz to 8-MHz crystals
• FLASH program memory security⁽¹⁾
• On-chip programming firmware for use with host personal computer which does not require high
voltage for entry
• In-system programming (ISP)
• System protection features:
– Optional computer operating properly (COP) reset
– Low-voltage detection with optional reset and selectable trip points for 3.0-V and 5.0-V
operation
– Illegal opcode detection with reset
– Illegal address detection with reset
• Low-power design; fully static with stop and wait modes
• Standard low-power modes of operation:
– Wait mode
– Stop mode
1. No security feature is absolutely secure. However, Freescale’s strategy is to make reading or copying the FLASH difficult for
unauthorized users.
MC68HC908GR8A • MC68HC908GR4A Data Sheet, Rev. 5
Freescale Semiconductor
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