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闪存(Flash Memory)是目前最新的一种ROM,它是1980年由美国Intel公司推出的,主要用来替代可编辑只读存储器(Erasable Programmable Read-only Memory,EPROM)。从它的名称上我们就可以知道它在存储信息时是闪电式的,也就是说信息能在一瞬间被存储下来,它是ROM就必然有掉电不失信息的特性,即在掉电情况下,存储的信息依旧保留。闪存是电可擦除的,也是在系统中可重编程的,而且闪存在擦除和重新编程时并不需要额外的电源。除非给它加一个高电压进行擦除,否则闪存中的信息一直保持不变(储存时间长达十年之久)。信息更新是以Block为单位的,而不是我们常见的Byte为单位,每个Block的长度在256kB～20MB之间。它的访问时间可低至30ns,比硬盘驱动器快100～1000倍,并且耗电量很低,这对便携机是非
Flash Memory is the latest ROM, which was introduced by Intel Corporation in 1980 mainly to replace Erasable Programmable Read-Only Memory (EPROM). From its name we can know that it is flashing when storing information, which means that the information can be stored in an instant, it is a ROM must have the power to lose information without losing the characteristics of the power-down situation Under the stored information is still retained. Flash is electrically erasable and reprogrammable in the system, and flash does not require additional power when it is erased and reprogrammed. Unless erased by applying a high voltage to it, the information in the flash remains the same (stored for as long as ten years). Information update is based on Block, rather than our common Byte as a unit, each Block length between 256kB ~ 20MB. Its access time can be as low as 30ns, 100 ~ 1000 times faster than the hard drive, and the power consumption is very low, which is non-portable