Read/Write MMC Card Based on SPI Protocol
ZHOU Yu,FU Yu-zhuo (School of Information Security Engineering, Shanghai Jiaotong Univ.,Shanghai 200030,China)
MMC Card is wildly used as storage media in multimedia field. But most MCUs don't have MMC controller. Most of MCUs support SPI bus which just needs four wires for communication. For those MCUs without MMC controllers, MMC protocol gives another choice,namely the SPI mode. In this mode, MCUs can communicate with MMC card through SPI bus. And it can support most commands in MMC protocol. SPI protocol, special functions for MMC card and implementation on DSP56858 platform are introduced in this article. Though I/O speed is a bit lower than that using controller, it can meet most of reguirements.