SD卡的资料整理！有sd卡驱动的51的例程、avr的例程以及一些可移植的c、h文件！-SD card data compilation! There are 51 sd card driver routines, avr s routine as well as some portable c, h files!

/*说明：AVR串口是通过UDR发送出去的，类似于51单片机的SBUF*/ /*程序功能:能够通过串行数据发送给PC机0x12数据，接收上位机数据并且+1后发送回上位机*/-uart communication implement