AN2295 Freescale Semiconductor / Motorola, AN2295 Datasheet - Page 3

• Manufacturer Part Number: AN2295
• Description: Developers Serial Bootloader for M68HC08 and HCS08 MCUs
• Manufacturer: Freescale Semiconductor / Motorola

Demo Features of Bootloader Application
This document describes several different M68HC(S)08 bootloader implementations which vary mainly
because the target M68HC(S)08 MCUs have different features. Several features of the M68HC(S)08
Family are also demonstrated, making this document useful to a wider audience than those who require
only the bootloader. The different M68HC(S)08 implementations also demonstrate the following features:
FC Protocol Description
As described in Requirements, an implementation must be as simple as possible and use as little memory
as possible. Therefore, the protocol running between the master PC and slave MCU is also very simple.
It is called FC protocol because one significant character (the acknowledge, or ACK) $FC or 11111100b
is used.
This section provides a description of the protocol that is used to communicate between the PC and target
MCU to reprogram the MCU. A general description is followed by an explanation of family-specific
implementation features.
Figure 2
in this document.
Freescale Semiconductor
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Use of built-in ROM routines for FLASH self-programming (see also AN1831/D in References).
User implementation of in-circuit reprogramming routines on ROM-less MCUs, such as the
MC68HC908GP32 Family
Use of different implementations of the FLASH block protection technique
(MC68HC908GP/GR/KX vs. MC68HC908JK/JL Families)
Implementation of software SCI on SCI-less MCUs, such as the MC68HC908JK/JL Family
Use of the internal clock generator and its trimming (for the MC68HC908KX Family)
EEPROM programming (for the MC68HC908AS/AZ Family)
is a simplified state diagram that shows separate states of the bootloader, which are described
Developer’s Serial Bootloader for M68HC08 and HCS08 MCUs, Rev. 6
FC Protocol Description
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