HCS08系列FLASH在线编程方法的比较与分析

Analysis and comparison of in-circuit programming for FLASH in HCS08 MCU family

针对HCS08系列FLASH在线编程过程中读取FLASH会产生不稳定的问题,提出3种不同的解决方案,即将擦除/写入子程序与擦写区域放在FLASH的不同块中、将擦除/写入子程序移入RAM中以及仅将引起FLASH不稳定的程序代码移入RAM中,并分析这些方案的特点及其技术实现要点.以HCS08系列的MC9S08AW60为例进行测试,并对实验结果进行详细分析.结果表明:这3种方案在编程方法和功能上各有自己的优缺点,同时也验证了将造成不稳定的程序机器码移入RAM中的方案简单、可靠,这为解决FLASH在线编程过程中的不稳定问题提供了新的思路.

During in-circuit programming for FLASH in Freescale′s HCS08 MCU family,there exists an unstable problem for writing or clearing FLASH.To solve the problem,three solutions are put forward,which are block of putting earse or write sub-program is not a block earsed or written,the sub-program is moved to RAM and programs resulting in FLASH unstable running is moved to RAM,and their features and key technology are discussed.MC9S08AW60 is taken as an example during debugging.By analyzing the experiments,we can know advantages and disadvantages of the three solutions in programming methods.The experimental results indicate the solution that the instructions leading up to FLASH unstable running moved to RAM is simple and reliable,which gives a new in solving the problem of unstable FLASH during in-circuit programming.