
MultiMediaCard
TM
10
Sep.22.2005
Revision 0.3
3.9 SPI Mode
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.
3.9.1 Negotiating Operation Conditions
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.
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.
3.9.2 Card Acquisition and Identification
In SPI mode only 16bits (containing the errors relevant to SPI mode) can be read out of the MultiMediaCard status regis-
ter.
3.9.3 Card status
Memory partioning in SPI mode is equivalent to MultiMediaCard mode. All read and write commands are byte address-
able.
3.9.4 Memroy Array Partitioning
In SPI mode, only single block read/write mode is supported.
3.9.5 Read and Write Operations
In SPI mode, only single block mode is supported. The typical access time (latency) for each data block, in read opera-
tion, 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.
3.9.6 Data Transfer Rate
Same as in the MultiMediaCard mode.
3.9.7 Data protection in the MultiMediaCard
Same as in the MultiMediaCard mode.
3.9.8 Erase