HB28E016/D032/D064/B128MM2
33
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 (cards stay in the Ready State).
There should be only one card which successfully sends its full CID-number to the host. This card then
goes into the Identification State. The host assigns to this card (using CMD3, SET_RELATIVE_ADDR) a
relative card address (RCA, shorter than CID), which will be used to address the card in future
communication (faster than with the CID). Once the RCA is received the card transfers to the Standby
State and does not react to further identification cycles. The card also switches the output drivers from the
open-drain to the push-pull mode in this state. The host repeats the identification process as long as it
receives a response (CID) to its identification command (CMD2). When no card 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.
Operating Voltage Range Validation
The MultiMediaCard standards operating range validation is intended to support reduced voltage range
MultiMediaCards. These Hitachi MultiMediaCards support the range of 2.7 V to 3.6V supply voltage. So
these Hitachi MultiMediaCards send a R3 response to CMD1 which contains an OCR value of
0x80FF8000 if the busy flag is set to “ready” or 0x00FF8000 if the busy flag is active (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.