MultiMediaCard Product Manual
28
SanDisk MultiMediaCard Product Manual Rev. 2 © 2000 SANDISK CORPORATION
4.5.3
Card Identification (CID) Register
The CID register is 16 bytes long and contains a
unique card identification number as shown in the
table below. It is programmed during card
manufacturing and can not be changed by
MultiMediaCard hosts.
Table 4-5 CID Fields
Name
T y p e
Width
CID -
S l i c e
Comments
Manufacturer ID
Binary
24
[127:104]
The manufacturer IDs are
controlled and assigned by
the MultiMediaCard
Association.
Product name
String
56
[103:48]
HW Revision
Binary
4
[47:44]
Card hardware revision.
FW Revision
Binary
4
[43:40]
Card firmware revision.
Serial Number
Binary
24
[39:16]
A unique card ID number.
Month code
Binary
4
[15:12]
Manufacturing date - month
Year code
Binary
4
[11:8]
Manufacturing date - year
(offset from 1997)
CRC7 checksum*
Binary
7
[7:1]
Calculated
Not used, always ‘1’
1
[0:0]
*Note:
The CRC Checksum is computed by the following formula:
CRC Calculation: G(x)=x7+3+1
M(x)=(MID-MSB)*x119+...+(CIN-LSB)*x0
CRC[6...0]=Remainder[(M(x)*x7)/G(x)]
4.5.4
CSD Register
The Card Specific Data (CSD) register contains
all the configuration information required in order
to access the card data.
In the table below, the cell type column defines
the CSD field as Read only (R), One Time
Programmable (R/W) or erasable (R/W/E). This
table shows, for each field, the value in “real
world” units and coded according to the CSD
structure. The Model dependent column marks
(with a check mark—
√
) the CSD fields which are
model dependent.