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S
S
D
D
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8
8
0
0
0
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r
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Rev1.2
SD80 Secure Digital Card
Transcend Information Inc.
13
The following sections describe the CSD fields and the relevant data types. If not explicitly defined otherwise, all bit
strings are interpreted as binary coded numbers starting with the left bit first.
•
CSD_STRUCTURE
Field structures of the CSD register are different depend on the Physical Specification Version and Card
Capacity.
The CSD_STRUCTURE field in the CSD register indicates its structure version.
The following table shows the version number of the related CSD structure.
CSD Register Structure
•
TAAC
This field is fixed to 0Eh, which indicates 1 ms. The host should not use TAAC, NSAC, and R2W_FACTOR to calculate
timeout and should uses fixed timeout values for read and write operations.
•
NSAC
This field is fixed to 00h. NSAC should not be used to calculate time-out values.
•
TRAN_SPEED
The following table defines the maximum data transfer rate per one data line - TRAN_SPEED:
