SDMJ-32 SanDisk, SDMJ-32 Datasheet - Page 41

• Manufacturer Part Number: SDMJ-32
• Manufacturer: SanDisk
• Type: MultiMedia Cardr

Specifications of SDMJ-32

• Density: 32MByte
• Operating Supply Voltage (typ): 3.3V
• Operating Temperature (min): -25C
• Operating Temperature (max): 85C
• Package Type: MMC
• Mounting: Socket
• Pin Count: 7
• Operating Temperature Classification: Commercial
• Operating Supply Voltage (min): 2.7V
• Operating Supply Voltage (max): 3.6V
• Programmable: Yes
• Lead Free Status / RoHS Status: Compliant

Revision 1.3
© 2005 SanDisk Corporation
4.1.3
Card Identification Process
VDD-min and VDD-max. However, during data transfer, minimum and maximum values
for VDD are defined in the CSD Register and may not cover the entire range. Card hosts
are expected to read the card’s CSD Register and select the proper VDD values or reject the
card.
A MultiMediaCard/RS-MultiMediaCard that stores the CID and CSD data in the payload
memory can communicate this information only under data-transfer VDD conditions. This
means if the host and card have incompatible VDD ranges, the card will not be able to
complete the identification cycle, nor to send CSD data.
SEND_OP_COND (CMD1) is designed to provide card hosts with a mechanism to identify
and reject cards that do not match the host’s desired VDD range. To accomplish this task,
the host sends the required VDD voltage window as the operand of this command.
MultiMediaCards/RS-MultiMediaCards that cannot perform data transfer in the specified
range must discard themselves from further bus operations and go into Inactive State. All
other cards will respond concurrently (same method as card identification) sending back
their VDD range. The wired-or result of the response will show all voltage ranges, some of
which the cards do not support.
By omitting the voltage range in the command, the host can query the card stacks and
determine if there are any incompatibilities before sending out-of-range cards into the
Inactive State. A bus query should be used if the host can select a common voltage range or
wants to notify the application of unusable cards in the stack.
The MultiMediaCard or RS-MultiMediaCard can use the busy bit in the CMD1 response to
tell the host that it is still working on the power-up/reset procedure (e.g., downloading the
register information from memory field) and is not ready for communication. In this case
the host must repeat CMD1 until the busy bit is cleared.
During the initialization procedure, the host is not allowed to change OCR values; the card
will ignore OCR content changes. If there is a actual change in the operating conditions,
the host must reset the card stack (using CMD0) and begin the initialization procedure
again.
GO_INACTIVE_STATE (CMD15) can also be used to send an addressed
MultiMediaCard/RS-MultiMediaCard into the Inactive State. CMD15 is used when the
host explicitly wants to deactivate a card—for example, the host changes VDD into a range
not supported by this card.
The host starts the card identification process in open-drain mode with the identification
clock rate f
during card identification.
After the bus is activated and a valid operation condition is obtained, the host asks all cards
for their unique card identification (CID) number with the broadcast command,
ALL_SEND_CID (CMD2). All remaining unidentified cards, those in Ready State,
simultaneously start sending their CID numbers serially, while bit-wise monitoring their
outgoing bit stream. The MultiMediaCards and RS-MultiMediaCards with outgoing CID
bits that 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
(cards stay in the Ready State). Because CID numbers are unique for each card, there
should be only one card that successfully sends its full CID number to the host; the cards
then goes into Identification State. The host issues CMD3, (SET_RELATIVE_ADDR) to
assign this card a relative address (RCA), which is shorter than CID and used to address the
card in future data transfer mode communication typically with a higher clock rate than
OD
. The open-drain driver stages on the CMD line allow parallel card operation
4-3
MultiMediaCard/RS-MultiMediaCard Product Manual
Chapter 4 – MultiMediaCard Protocol Description
04/22/05