rc522代码，在c51和c430移植两个版本。实现rf卡读取写入等。-rc522 code in the two versions of the c51 and c430 transplantation. Achieve rf cards such as read-write.

Cortex-M0控制RC522型号的RFID芯片，本代码用于该型号的RFID测试-Cortex-M0 control RC522 type of RFID chip, the code for the type of RFID test