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Rev1.2
SD80 Secure Digital Card
Transcend Information Inc.
18
4. RCA Register
The writable 16-bit relative card address register carries the card address that is published by the card during the card
identification. This address is used for the addressed host-card communication after the card identification procedure.
The default value of the RCA register is 0x0000. The value0x0000 is reserved to set all cards into the
Stand-by State
with CMD7.
5. DSR Register (Optional)
It can be optionally used to improve the bus performance for extended operating conditions (depending on parameters
like bus length, transfer rate or number of cards). The CSD register carries the information about the DSR register
usage. The default value of the DSR register is 0x404.
6. SCR Register
In addition to the CSD register there is another configuration register that named - SD CARD Configuration
Register
(SCR). SCR provides information on SD Memory Card's special features that
were configured into the given card. The
size of SCR register is 64 bit. This register shall be set in
the factory by the SD Memory Card manufacturer.
The following table describes the SCR register content.
•
SCR_STRUCTURE
Version number of the related SCR structure in the SD Memory Card Physical Layer Specification.
SCR Register Structure Version
