sdcard-cid-decode

Decode the Card Identification (CID) of an SD card on Node.js and the browser.

This module will extract the information in the CID of an SD card. The CID can typically be found in /sys/block/mmcblk0/device/cid.

Breaking changes in 2.0.0

• CommonJS default export: require('sdcard-cid-decode') now returns the function directly. Previously it returned { default: fn } and consumers had to write require('sdcard-cid-decode').default. ESM import decodeCID from 'sdcard-cid-decode' is unchanged.
• CRC7 checksum value: crc7Checksum now returns the 7-bit CRC value as defined by the SD specification (the trailing byte right-shifted by 1 to drop the stop bit). Previous versions returned the raw trailing byte including the stop bit. If you compared this value against externally-computed CRC7s, you were comparing the wrong number; the new value is correct.
• Input validation: decodeCID() now throws TypeError for non-string or non-hex input and RangeError for inputs that are not 32 hex characters. Previously it silently produced garbage.
• Manufacturer name fixes: 0x000027 is now spelled Phison (was Phision), 0x000002 is now Kioxia (was Toshiba, rebranded in 2019), 0x00001d is now ADATA (was AData).
• Node 18+ required.

Installation

npm install --save sdcard-cid-decode

Example

ESM:

import fs from 'node:fs';
import decodeCID from 'sdcard-cid-decode';

const cid = fs.readFileSync('/sys/block/mmcblk0/device/cid', 'utf8');

const info = decodeCID(cid);
console.log(info);

// {
//   manufacturerId: '0x000003',
//   manufacturerIdDecimal: 3,
//   manufacturer: 'SanDisk',
//   oemId: 'SD',
//   productName: 'SL16G',
//   productRevision: '8.0',
//   serialNumber: 724511351,
//   manufactureDate: '03/2019',
//   crc7Checksum: 0
// }

CommonJS:

const decodeCID = require('sdcard-cid-decode');

const info = decodeCID('27504853443332473001b44eed00f221');
console.log(info);

// {
//   manufacturerId: '0x000027',
//   manufacturerIdDecimal: 39,
//   manufacturer: 'Phison',
//   oemId: 'PH',
//   productName: 'SD32G',
//   productRevision: '3.0',
//   serialNumber: 28593901,
//   manufactureDate: '02/2015',
//   crc7Checksum: 16
// }

API

type CardIdentification

• manufacturerId: string: Hex representation of the manufacturer ID assigned by SD-3C, LLC.
• manufacturerIdDecimal: number: Decimal representation of the manufacturer ID assigned by SD-3C, LLC
• manufacturer: string: A guessed manufacturer name based on this list, this list, and the Linux kernel. If the name is unknown then value will be "Unknown"
• oemId: string: OEM / Application ID assigned by SD-3C, LLC
• productName: string: Product name
• productRevision: string: Product revision
• serialNumber: number Serial number
• manufactureDate: string: Manufacture date
• crc7Checksum: 7-bit checksum

decodeCID(cid: string): CardIdentification

Decodes a CID and returns all the information.

License

Copyright (c) 2021-2026 Max Kueng

MIT License