MC68HC908GR8 Datasheet, PDF (19/286 Pages) Freescale Semiconductor, Inc – M68HC08 Microcontrollers

Chapter 1
General Description
1.1 Introduction
The MC68HC908GR8 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 MC68HC908GR4. The MC68HC908GR4 is a device identical to the
MC68HC908GR8 except that it has less Flash memory. Only when there are differences from the
MC68HC908GR8 is the MC68HC908GR4 specifically mentioned in the text.
1.2 Features
For convenience, features have been organized to reflect:
• Standard features of the MC68HC908GR8
• Features of the CPU08
1.2.1 Standard Features of the MC68HC908GR8
• High-performance M68HC08 architecture optimized for C-compilers
• Fully upward-compatible object code with M6805, M146805, and M68HC05 Families
• 8-MHz internal bus frequency
• 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
• 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
• Master reset pin and power-on reset (POR)
1. No security feature is absolutely secure. However, Freescale’s strategy is to make reading or copying the FLASH difficult for
unauthorized users.
MC68HC908GR8 • MC68HC908GR4 Data Sheet, Rev. 7
Freescale Semiconductor
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