MultiMediaCard Protocol - USB Mass Storage: Designing and Programming Devices and Embedded Hosts - page 101

Table 5-4: Mandatory basic-class commands for a MultiMediaCard.
Index

Abbreviation Argument Response Description

CMD0 GO_IDLE_STATE none R1 Reset the card to the idle state.

CMD1 SEND_OP_COND none R1 Activate the card's initialization

process.

CMD9 SEND_CSD none R1 Request the contents of the CSD

register. The register's contents
follow the response token.

CMD10 SEND_CID none R1 Request the contents of the CID

register. The register's contents
follow the response token.

CMD13 SEND_STATUS none R2 Request status information

CMD58 READ_OCR none R3 Read the operation conditions

register. The register's contents
are in the response token.

CMD59 CRC_ON_OFF 31..1:

stuff bits;
0:
CRC option

R1 Bit 0 = 1: use CRC.

Bit 0 = 0: ignore CRC.

This value is the offset of the byte within the media, with the bytes num-
bered sequentially from zero. To convert a logical block address (LBA) to a
byte address, multiply the LBA by the media's block, or sector, size (typically
512).

Registers
Some commands read or write to registers in the MultiMediaCard. Table
5-6 shows the three MultiMediaCard registers used in SPI communications.
The MultiMediaCard bus supports two additional registers for storing a
card address and providing data to improve bus performance. These registers
are unneeded and unavailable in SPI mode.

Sending Commands
Most MultiMediaCard commands are in one of three categories: commands
that transmit no data blocks to or from the storage media, commands where
the MultiMediaCard host sends data to the storage media, and commands
where the MultiMediaCard host receives data from the storage media. For