SHDC协议，SD2.0。单片机开发，大容量的SD卡开发协议，2G以下与2G以上的SD,microSD卡协议不一样。一个可以用SPI，另一个可以用SD协议-The SHDC agreement, SD 2.0. MCU development, large-capacity SD card development agreement, 2G following agreement with more than 2G SD and microSD card is not the same. One

本文档详细说明了利用SD卡来扩展数据存储空间的方法，是本很好的参考资料。-This document details the use of SD card to expand the data storage method is the very good reference.

SD2.0协议全套，不太好找的。希望对大家有用。-SD2.0 complete agreement, not very good looking.