MICROSDHC datasheet(16/25 Pages) TRANSCEND | High Capacity microSD Card

16 / 25 page

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High Capacity microSD Card

Transcend Information Inc.

Note that for current SD Memory Cards that field must be always 0_0110_010b (032h) which is equal to 25MHz - the

mandatory maximum operating frequency of SD Memory Card.

In High-Speed mode, that field must be always 0_1011_010b (05Ah) which is equal to 50MHz. And when the timing

mode returns to the default by CMD6 or CMD0 command, its value will be 032h.

• CCC

The SD Memory Card command set is divided into subsets (command classes). The card command class register CCC

defines which command classes are supported by this card. A value of ‘1’ in a CCC bit means that the corresponding

command class is supported.

• READ_BL_LEN

This field is fixed to 9h, which indicates READ_BL_LEN=512 Byte.

• READ_BL_PARTIAL

This field is fixed to 0, which indicates partial block read is inhibited and only unit of block access is allowed.

• WRITE_BLK_MISALIGN

This field is fixed to 0, which indicates write access crossing physical block boundaries is always disabled in High

apacity SD Memory Card.

• READ_BLK_MISALIGN

This field is fixed to 0, which indicates read a

disabled in High Capacity SD Memory Card.

ccess crossing physical block boundaries is always

• DSR_IMP

Defines if the configurable driver stage is integrated on the card. If set, a driver stage register (DSR)must be

implemented also.

MICROSDHC Datasheet(PDF) 16 Page - Transcend Information. Inc.