sd卡结构详细文件，你要的应该就是这个PDF文件了吧-The SD BUS Core with Avalon Interface allows the easy access of

SOPC Builder systems to standard Secure Digital Card (SD) flash based

memory devices. The SD cards are universal, low cost data storage and

communication media, which are generally available and widely used

in consumer products such as digital cameras or cellular phones. The

SD BUS Core is fully compliant with SOPC Builder and integrates easily

into any SOPC Builder generated system.