摘要
在测量、控制等领域的应用中,常要求单片机内部和外部RAM中的数据在电源掉电时不丢失,重新加电时,RAM中的数据能够保存完好,这就要求对单片机系统加接掉电保护电路.掉电保护通常可采用以下3种方法:一是加接不间断电源,让整个系统在掉电时继续工作,二是采用备份电源,掉电后保护系统中全部或部分数据存储单元的内容;三是采用EEPROM来保存数据.由于第1种方法体积大、成本高,对单片机系统来说,不宜采用.第2种方法是根据实际需要,掉电时保存一些必要的数据,使系统在电源恢复后,能够继续执行程序,因而经济实用,故大量采用.EEPROM既具有ROM掉电不丢失数据的特点,又有RAM随机读写的特点.但由于其读写速度与读写次数的限制,使得EEPROM不能完全代替RAM.介绍最常用的一些掉电保护的处理方法,希望能对相关设计人员在实际工作中有所帮助.
As the application in the area of measure and control,the data in RAM internal or external the singlechip is desired not to be lost,when the power supply is off,data in RAM can be saved in good condition when Power is on.So protective circuit is desired for the singlechip system.AC dump shield is usually approved in three means:first of all,picking up UPS make overall system in AC dump time work on.Secondly,the adoption of backup battery content,when power is off,the whole or partial content in data location of the system is protected.The last,EEPROM is adopted to save data.As the large volume and high cost,the first means is not suitable for the singlechip system.The second means is adopted widely owing to its economical and practical,as it can save some necessary data when power down,so that,when power supply is restored,program can be continue.EEPROM has the behaviour of ROM,that's obliterated data when power down of,as well as the behaviour of ram,random read-write.But owing to limitation of its read-write speed and degree,EEPROM can not perfect substitution ram.Some most used processing method of power down protective are introduced,hoping it can do something in the real worldfor design staff.
出处
《云南大学学报（自然科学版）》
CAS
CSCD
北大核心
2007年第S1期135-138,共4页
Journal of Yunnan University(Natural Sciences Edition)
关键词
单片机应用系统
RAM
数据保护电路
singlechip application system
RAM
data protection circuit
