MMCSDTimming MMC卡的时序图，比起SD规范又臭又长的文档，要简洁的多了。SD卡也可以以此作为参考-MMCSDTimming MMC card timing diagram, compared to SD specification also documents a long foul, it is necessary to more concise. SD card can also be used as a reference

SD卡1.0规范文档，英文版文档，简单实用。-SD Card 1.0 specification document, English version of the document