说明：  SLE4428的C51程序源码，已经过调试，实现了对44428卡片的读写校验密码等操作 可直接使用。 已通过测试。
(The SLE4428 the C51 program source code has been commissioning, 44428 card read and write calibration password, and other operations can be used directly. Has been tested.)