HB288032MM1 Datasheet, PDF (53/80 Pages) Hitachi Semiconductor – MultiMediaCard 32 MByte

HB288032MM1
Erase and Write Protect Management
The erase and write protect management procedures in the SPI mode are identical to those of the
MultiMediaCard mode. While the card is erasing or changing the write protection bits of the predefined
sector list, it will be in a busy state and hold the DataOut line low. Figure “No Data Operations” illustrates
a ‘no data’ bus transaction with and without busy signalling.
Data in
from
host
to card
command
from
card
to host
from
host
to card
command
from
card
to host
Data out
response
‘No Data’ Operations
response busy
Reading CID/CSD Registers
Unlike the MultiMediaCard protocol (where the register contents are sent as a command response), reading
the contents of the CSD and CID registers in SPI mode is a simple read-block transaction. The card will
respond with a standard response token (refer to Figure “Read Operation”) followed by a data block of 16
bytes suffixed with a 16 bit CRC. The data timeout for the CSD command cannot be set to the card TAAC
since this value is stored in the CSD. Therefore the standard response timeout value (N_CR) is used for read
latency of the CSD register.
Reset Sequence
The MultiMediaCard requires a defined reset sequence. After power on reset or CMD0 (software reset) the
card enters an idle state. At this state the only legal host command is CMD1 (SEND_OP_COND) and
CMD58 (READ_OCR). In SPI mode, as opposed to MultiMediaCard mode, CMD1 has no operands and
does not return the contents of the OCR register. Instead, the host may use CMD58 (available in SPI mode
only) to read the OCR register. Furthermore, it is in the responsibility of the host to refrain from accessing
cards that do not support its voltage range. The usage of CMD58 is not restricted to the initializing phase
only, but can be issued at any time. The host must poll the card (by repeatedly sending CMD1) until the
‘in-idle-state’ bit in the card response indicates (by being set to 0) that the card completed its initialization
processes and is ready for the next command. The host must poll the card (by repeatedly sending CMD1)
until the ‘in-idle-state’ bit in the card response indicates (by being set to 0) that the card completed its
initialization processes and is ready for the next command.
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