Emmc Cid Decoder May 2026

Most Linux systems expose the CID via sysfs. Run:

cat /sys/block/mmcblk0/device/cid

That outputs a 32-character hex string (128 bits). Example:

150100303136473332e03f5d9600b46d

Now, let’s decode it using a simple Python snippet or an online tool.

Quick manual decode (offsets, 0-indexed):

cid = "150100303136473332e03f5d9600b46d"
mid = cid[0:2]          # 0x15 (Kingston)
oem = cid[2:6]          # 0x0100
pnm = bytes.fromhex(cid[6:18]).decode()  # "016G32"
prv = cid[18:20]        # 0xe0 → revision 1.0?
psn = cid[20:28]        # 0x3f5d9600
mdt = cid[28:32]        # 0xb46d → year/mon decode

Or use mmc-utils:

sudo mmc extcsd read /dev/mmcblk0 | grep -i cid

If the device won't boot, you need an eMMC hardware programmer like: emmc cid decoder

These tools read the CID directly via the eMMC bus (CLK, CMD, D0) using a soldered or pogo-pin connection.

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Developers often need to bind software licenses to a hardware ID. Since the CID is immutable, it is a better hardware fingerprint than MAC addresses (which can be spoofed). Decoding allows scripts to read /sys/block/mmcblk0/device/cid and extract the serial number or manufacturer.

A raw 128-bit hexadecimal string like FE014A4D4247470... is unintelligible to a human. The decoder transforms this binary gibberish into readable information.

| MID (hex) | Manufacturer | | :--- | :--- | | 0x02 | Sandisk / Western Digital | | 0x03 | Toshiba (now Kioxia) | | 0x11 | Samsung | | 0x13 | Micron | | 0x1C | Hynix (SK Hynix) | | 0x45 | Kingston |

(Full list available from JEDEC publication JEP106)

eMMC CID (Card Identification) decoder is a tool or script used to translate the raw 128-bit hexadecimal string stored in an eMMC device's CID register into human-readable information. This register serves as a unique "fingerprint" for the storage chip, containing essential manufacturing and device-specific metadata. The Role of the CID Register

The CID is a mandatory register in all JEDEC-compliant eMMC devices. It is primarily used by system developers, repair technicians, and forensic analysts to: www.chipstar.ru Verify Authenticity Most Linux systems expose the CID via sysfs

: Confirm if a chip is from a genuine manufacturer like Samsung, Micron, or SK Hynix. Debug Hardware

: Identify specific silicon revisions or production dates that may be prone to failure. Match Components

: Ensure the eMMC's unique ID matches the expected ID programmed into a device's CPU, a common security measure in smartphones. Decoded Fields and Their Meaning A standard eMMC CID string contains several defined fields: MID (Manufacturer ID)

: An 8-bit ID assigned by the JEDEC committee to the chip maker. OID (OEM/Application ID)

: A 16-bit identifier for the original equipment manufacturer or specific application. PNM (Product Name)

: A 6-character ASCII string representing the model name (e.g., "MAG2GA"). PRV (Product Revision)

: A 2-digit BCD code indicating the hardware and firmware version. PSN (Product Serial Number) : A unique 32-bit integer assigned during production. MDT (Manufacturing Date) : Encoded year and month of production. : A checksum used to verify the integrity of the CID data. How to Extract and Decode CID Data That outputs a 32-character hex string (128 bits)

To decode a CID, you must first read the raw hex string from the device:

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For offline or batch decoding, Python scripts are ideal. Below is a simple yet complete eMMC CID decoder.

#!/usr/bin/env python3
# eMMC CID Decoder
import sys
def decode_emmc_cid(cid_hex):
cid_bytes = bytes.fromhex(cid_hex)
if len(cid_bytes) != 16:
raise ValueError("CID must be 32 hex chars (16 bytes)")
# MID
mid = cid_bytes[0]
manufacturers = 0x15: "Samsung", 0x11: "Toshiba", 0xFE: "SanDisk", 0x45: "Sandisk", 0x03: "Hynix", 0x01: "Samsung", 0x00: "No manufacturer"
print(f"Manufacturer ID (MID): 0xmid:02X (manufacturers.get(mid, 'Unknown'))")
# OID
oid = cid_bytes[2]
print(f"OEM ID (OID): 0xoid:02X")
# Product Name (PNM) - bytes 3 to 8 (6 chars)
pnm = cid_bytes[3:9].decode('ascii', errors='ignore').strip('\x00')
print(f"Product Name (PNM): pnm")
# Product Revision (PRV)
prv = cid_bytes[9]
rev_major = (prv >> 4) & 0x0F
rev_minor = prv & 0x0F
print(f"Product Revision (PRV): rev_major.rev_minor (BCD)")
# Serial Number (PSN) - bytes 10,11,12,13
psn = int.from_bytes(cid_bytes[10:14], byteorder='big')
print(f"Serial Number (PSN): psn (0xpsn:08X)")
# Manufacturing Date (MDT) - bits from byte 14 (nibbles)
mdt_byte = cid_bytes[14]
year_nibble = (mdt_byte >> 4) & 0x0F
month_nibble = mdt_byte & 0x0F
# Year offset from 1997 (JEDEC standard)
year = 1997 + year_nibble
print(f"Manufacturing Date: year:04d-month_nibble:02d (nibble year offset)")
# CRC7
crc_byte = cid_bytes[15] >> 1
print(f"CRC7: 0xcrc_byte:02X")

if name == "main":
if len(sys.argv) != 2:
print("Usage: python emmc_cid_decoder.py <32-char-hex-cid>")
sys.exit(1)
decode_emmc_cid(sys.argv[1])

Save as cid_decoder.py and run:

python cid_decoder.py 1501004242473541021A79C0D5012B