Insert the card and look under /sys/block/mmcblk0/device/ (this location may change depending on your platform, it may be mmcblk1 or in a different location). With Linux, reading the internal SD card information is simple. Not all computers with built-in card slots will work, some internal card readers are connected through a USB bus.Īssuming you have the proper hardware, there are several methods you can use to get the card information. This will not work through a USB card reader because the command to retrieve the card information is intercepted and not understood by card readers. Card readers in laptops are usually connected directly through the PCI bus (or IDE bus). One way to read the CID is to use a laptop with an SD card slot. (According to SD card specification the information is only to be written once, however if a card does not conform to the specification this information could be changed!) How to read the CID from an SD card The CID register is set when the card is manufactured and cannot be changed after it is set. One of these is the Card Identification (CID) Register, a 16 byte code that contains information that uniquely identifies the SD card, including the card serial number (PSN), manufacturer ID number (MID) and manufacture date (MDT). This is the checksum of the CID contents computed as described in SD Specification.Information about an SD card is encoded in its internal card registries. The manufacturing date is composed of two hexadecimal digits one is 8 bits representing the years(y) and the other is 4bits representing the month (m).ĬRC7 checksum (7 bits). The Serial Number is 32bits of binary 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 0010b The product revision is composed of two Binary Coded Decimal (BCD) digits, four bits each, representing an The product name is a string, 5-character ASCII string. Ltd., SanDisk Corporation and Toshiba Corporation. Note: SD-3C, LLC licenses companies that wish to manufacture and/or sell SD Memory Cards, including but not limited to flash memory, ROM, OTP, RAM, and SDIO Combo Cards SD-3C, LLC is a limited liability company established by Matsushita Electric Industrial Co. This procedure is established to ensure uniqueness of the CID register. 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.Ī 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 MID number is controlled, defined, and allocated to a SD Memory Card manufacturer by the SD-3C, LLC. The structure of the CID register is defined in the following paragraphs:īinary number of 8-bit that identifies the manufacturer of the card. Every individual Read/Write (RW) card shall have a unique identification number. It contains the card identification information used during the card identification phase. The Card Identification (CID) register is 128 bits wide. 三、Contact our fill in the following Review form: 一、Change by yourself? It's difficult and expensive.īecause special equipment and software and professional technology are needed.ģ) Settings are initialized through the factory. Is the SD Card CID number you need below?Ĭompatible to: Car GPS Navigator, pos machine, printer
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