单片机控制高容量安全数字卡的应用设计

摘要

为了解决高容量安全数字卡在嵌入式系统中不能访问的问题,通过分析高容量安全数字卡与标准容量安全数字卡的差异,提出了用串行外设接口访问控制高容量安全数字卡的方法,用飞思卡尔MC9S12XS128单片机作为嵌入式微处理器,用宇瞻4千兆字节的高容量安全数字卡作为控制对象,设计了高容量安全数字卡的控制电路和访问程序.先用单片机向高容量安全数字卡的指定扇区中写入数据,然后用单片机读取安全数字卡中所写入的数据,最后对所读出的数据与所写入的数据进行比较.实验表明,单片机所读出的数据与写入高容量安全数字卡的数据一致,采用串行外设接口访问控制高容量安全数字卡可以实现嵌入式系统的存储器升级.%In order to solve the problem that the high capacity digital card cannot be accessed in the embedded system, we put forward the method of controlling the high capacity secure digital card by the serial peripheral interface access after analyzing the difference between the high capacity secure digital card and standard capacity secure digital card. With Freescale single chip MC9S12XS128 chosen as an embedded microprocessor and the high capacity secure digital card of an Apacera 4Ciga byte as the controlled object, the control circuit and the access program of the high capacity secure digital card were designed . First , the single chip wrote the data to the designated sector of the high capacity secure digital card, and then read the written data in the card, finally the written data were compared with the read data. The experimental result shows that the read data agree with the written data and the instrument can be applied in the embedded systems upgrade.