MC2GH256NMCA-2SA00 SAMSUNG [Samsung semiconductor], MC2GH256NMCA-2SA00 Datasheet - Page 41

• Manufacturer Part Number: MC2GH256NMCA-2SA00
• Description: SAMSUNG MultiMediaCard
• Manufacturer: SAMSUNG [Samsung semiconductor]

TM
MultiMediaCard
Revision 0.3
The command CMD1 shall be implemented by all cards defined by this standard.
If the host intends to operate the Dual Voltage MultiMediaCards in the 1.65V to 1.95V range, it is recommended that the
host first validate the operating voltage in the 2.7V to 3.6V range, then power the card down fully, and finally power the
card back up to the 1.65V to 1.95V range for operation. Using the 2.7V to 3.6V range initially, which is common to High
and Dual voltage MultiMediaCards, will allow reliable screening of host & card voltage incompatibilities. High voltage cards
may not function properly if VDD < 2.0V is used to establish communication. Dual voltage cards may fail if 1.95 to 2.7V is
used.
6.1.3 Card Identification Process
The following explanation refers to a card working in a multi-card environment, as defined in versions of this standard pre-
vious to v4.0, and it is maintained for backwards compatibility to those systems.
The host starts the card identification process in open-drain mode with the identification clock rate f
(see Chapter 5.4.8).
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The open drain driver stages on the CMD line allow parallel card operation during card identification.
After the bus is activated, the host will request the cards to send its valid operation conditions (CMD1). The response to
CMD1 is the ‘wired and’ operation on the condition restrictions of all cards in the system. Incompatible cards are sent into
Inactive State. The host then issues the broadcast command ALL_SEND_CID (CMD2), asking all cards for its unique card
identification (CID) number. All unidentified cards (i.e. those which are in Ready State) simultaneously start sending their
CID numbers serially, while bit-wise monitoring their outgoing bitstream. Those cards, whose outgoing CID bits do not
match the corresponding bits on the command line in any one of the bit periods, stop sending their CID immediately and
must wait for the next identification cycle (remaining in the Ready State). Since CID numbers are unique for each card,
there should be only one card which successfully sends its full CID-number to the host. This card then goes into Identifica-
tion State. Thereafter, the host issues CMD3 (SET_RELATIVE_ADDR) to assign to this card a relative card address
(RCA), which is shorter than CID and which will be used to address the card in the future data transfer mode (typically with
a higher clock rate than f
). Once the RCA is received the card state changes to the Stand-by State, and the card does
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not react to further identification cycles. Furthermore, the card switches its output drivers from open-drain to push-pull.
The host repeats the identification process, i.e. the cycles with CMD2 and CMD3 as long as it receives a response (CID)
to its identification command (CMD2). If no more card responds to this command, all cards have been identified. The time-
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out condition to recognize completion of the identification process is the absence of a start bit for more than
clock
ID
cycles after sending CMD2 (see timing values in Chapter 6.11).
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Sep.22.2005