MultiMediaCardTM
The host can read the CSD register and alter the host controlled data bytes using the SEND_CSD and
PROGRAM_CSD commands.
2.7 SPI Mode
The SPI mode is a secondary (optional) communication protocol offered for MultiMediaCard. This
mode is a subset of the MultiMediaCard protocol, designed to communicate with an SPI channel,
commonly found in Motorola’s (and lately a few other vendors’) microcontrollers.
2.7.1 Negotiating Operation Conditions
The operating condition negotiation function of the MultiMediaCard bus is not supported in SPI mode.
The host must work within the valid voltage range (2.7 to 3.6 volts) of the card.
2.7.2 Card Acquisition and Identification
The card acquisition and identification function of the MultiMediaCard bus is not supported in SPI mode.
The host must know the number of cards currently connected on the bus. Specific card selection is
done via the CS signal.
2.7.3 Card Status
In SPI mode only 16 bits (containing the errors relevant to SPI mode) can be read out of the
MultiMediaCard status register.
2.7.4 Memory Array Partitioning
Memory partitioning in SPI mode is equivalent to MultiMediaCard mode. All read and write commands
are byte addressable.
2.7.5 Read and Write Operations
In SPI mode, only single block read/write mode is supported.
2.7.6 Data Transfer Rate
In SPI mode only block mode is supported. The typical access time (latency) for each data block, in
read operation, is 1.5mS. The write typical access time (latency) for each data block, in read operation,
is 1.5mS. The write block operation is done in handshake mode. The card will keep DataOut line low
as long as the write operation is in progress and there are no write buffers available.
2.7.7 Data Protection in the MultiMediaCard
Same as for the MultiMediaCard mode.
2.7.8 Erase
Same as in MultiMediaCard mode
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