Data Sheet

3.2 CID register
The Card Identification (CID) register is 128 bits wide. It contains the card identification information used
during the card identification phase. Every individual flash card shall have a unique identification number. The
structure of the CID register is defined in the following paragraphs:
• MID
An 8-bit binary number that identifies the card manufacturer. The MID number is controlled, defined, and
allocated to a SD Memory Card manufacturer by the SD-3C, LLC. This procedure is established to ensure
uniqueness of the CID register.
• OID
A 2-character ASCII string that identifies the card OEM and/or the card contents (when used as a distribution
media either on ROM or FLASH cards). The OID number is controlled, defined, and allocated to a SD Memory
Card manufacturer by the SD-3C, LLC. This procedure is established to ensure uniqueness of the CID register.
•PNM
The product name is a string, 5 ASCII characters long.
PNM can be customized by Transcend
• PRV
The product revision is composed of two Binary Coded Decimal (BCD) digits, four bits each, representing an
“n.m” revision number. The “n” is the most significant nibble and “m” is the least significant nibble.
As an example, the PRV binary value field for product revision “6.2” will be: 0110 0010
PRV can be customized by Transcend