hb288064mm1 Renesas Electronics Corporation., hb288064mm1 Datasheet - Page 30

• Manufacturer Part Number: hb288064mm1
• Description: Multimediacard 64 Mbyte
• Manufacturer: Renesas Electronics Corporation.

HB288064MM1
Card identification mode
All the data communication in the card identification mode uses only the command line (CMD).
The host starts the card identification process in open drain mode with the identification clock rate f
(generated by a push pull driver stage). The open drain driver stages on the CMD line allow the parallel
card operation during card identification. After the bus is activated the host will request the cards to send
their valid operation conditions with the command SEND_OP_COND (CMD1). Since the bus is in open
drain mode, as long as there is more than one card with operating conditions restrictions, the host gets in
the response to the CMD1 a “wired or” operation condition restrictions of those cards. The host then must
pick a common denominator for operation and notify the application that cards with out of range
parameters (from the host perspective) are connected to the bus. Incompatible cards go into Inactive State
(refer to also Chapter “Operating Voltage Range Validation”). The busy bit in the CMD1 response can be
used by a card to tell the host that it is still working on its power-up/reset procedure (e.g. downloading the
register information from memory field) and is not ready yet for communication. In this case the host must
repeat CMD1 until the busy bit is cleared. After an operating mode is established, the host asks all cards
for their unique card identification (CID) number with the broadcast command ALL_SEND_CID (CMD2).
All not already identified 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
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card is busy or
host omitted
voltage range
card looses bus
Power on
Indentification state
MultiMediaCard State Diagram (Card Identification Mode)
Stand-by state
Ready state
Idle state
(stby)
(ready)
CMD1
CMD2
(ident)
CMD3
(idle)
cards with non-compatible voltage range
card wins bus
card-indentification mode
data-transfer mode
CMD0
Inactive state
(ina)
from all states except (ina)
from all states in data-transfer mode
CMD15
OD