MC56U032DCCA Datasheet, PDF (35/64 Pages) Samsung semiconductor – Dual Voltage MultiMediaCard Specification

MultiMediaCard^TM
responds to this command, all cards have been identified. The time-out condition to recognize this, is
waiting for the start bit for more than 5 clock periods after sending CMD2
4.8.1 Operating Voltage Range Validation
The MultiMediaCard standards operating range validation is intended to support reduced voltage range
MultiMediaCards. The MultiMediaCard supports the range of 1.70V to 1.95V and 2.7V to 3.6V supply
voltage. So the MultiMediaCard sends a R3 response to CMD1 which contains an OCR value of either
0x80FF8080 if the card is ready, or 0x00FF8080 if the internal start-up procedure is not finished (refer
to Chapter “Responses”). By omitting the voltage range in the command, the host can query the card
stack and determine the common voltage range before sending out-of-range cards into the Inactive
State. This bus query should be used if the host is able to select a common voltage range or if a
notification to the application of non usable cards in the stack is desired. Afterwards, the host must
choose a voltage for operation and reissue CMD1 with this condition sending incompatible cards into
the Inactive State.
4.9 Data Transfer Mode
When in Standby State, both CMD and DAT lines are in the push-pull mode. As long as the content of
all CSD registers is not known, the f _PushPull clock rate is equal to the slow f _OpenDrain clock rate.
SEND_CSD (CMD9) allows the host to get the Card Specific Data (CSD register), e.g. ECC type, block
length, card storage capacity, maximum clock rate etc..
Figure 4-3 MultiMediaCard State Diagram (Data Transfer Mode)
The command SELECT_DESELECT_CARD (CMD7) is used to select one card and place it in the
Transfer State. If a previously selected card is in the Transfer State its connection with the host is
released and it will move back to the Stand-by State. Only one card can be, at any time, in the Transfer
State. A selected card is responding the CMD7, the deselected one does not respond to this command.
When CMD7 is sent including the reserved relative card address “0x0000”, all cards transfer back to
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