FLASH的编程原理都是只能将1写为0，而不能将0写为1.所以在FLASH编程之前，必须将对应的块擦除，而擦除的过程就是把所有位都写为1的过程，块内的所有字节变为0Xff。

　　对FALSH进行的最基本操作由读操作，写操作，和擦除操作。以下将详细介绍，所有的都是参考sst39vf1601 datasheet

-FLASH programming principles are the only one written as 0, can not be written as one. Before FLASH programming must be the corresponding block erase, erased all of the bits are written for a process, all within a block of bytes into 0Xff. The most basic operations on FALSH read, write and erase operations. The following details are reference sst39vf1601 datasheet