Emmc Cid Decoder -

| Bit Position | Field Name | Size (bits) | Description | |--------------|------------|-------------|-------------| | [127:120] | MID | 8 | Manufacturer ID (JEDEC-assigned) | | [119:112] | CBX | 8 | Card/BGA (not widely used) | | [111:104] | OID | 8 | OEM/Application ID | | [103:96] | PNM (first char) | 8 | Product name (character 1) | | [95:88] | PNM (second char) | 8 | Product name (character 2) | | [87:80] | PNM (third char) | 8 | Product name (character 3) | | [79:72] | PNM (fourth char) | 8 | Product name (character 4) | | [71:64] | PNM (fifth char) | 8 | Product name (character 5) | | [63:56] | PNM (sixth char) | 8 | Product name (character 6) | | [55:48] | PRV | 8 | Product revision (BCD) | | [47:40] | PSN (byte 1) | 8 | Product serial number (MSB) | | [39:32] | PSN (byte 2) | 8 | Product serial number | | [31:24] | PSN (byte 3) | 8 | Product serial number | | [23:16] | PSN (byte 4) | 8 | Product serial number (LSB) | | [15:12] | MDT (year) | 4 | Manufacturing date (year) | | [11:8] | MDT (month) | 4 | Manufacturing date (month) | | [7:1] | CRC | 7 | CRC7 checksum | | [0] | - | 1 | Reserved (always 1) |

Note: Some older eMMC versions have slight variations, but most modern devices conform to this layout.

The CID is a 128-bit register programmed by the card manufacturer that uniquely identifies an eMMC device. Fields and lengths follow the JEDEC and SD specifications adapted for eMMC (fields may vary by manufacturer/extended specs).

| Field | Bytes | Description | | :--- | :--- | :--- | | MID | 0 | Manufacturer ID. I mapped the most common IDs (Samsung, SanDisk, Toshiba, Micron) in the script. | | OID | 1-2 | OEM/Application ID. Usually 2 characters hex identifying the card customer or specific application. | | PNM | 3-8 | Product Name. ASCII string (up to 6 characters). Often model numbers like "BJTD4R" or "8GTF4". | | PRV | 9 | Product Revision. Binary Coded Decimal (BCD). 0x18 = Rev 1.8. | | PSN | 10-13 | Product Serial Number. A 32-bit unique integer. | | MDT | 14 | Manufacturing Date. 4 bits for Month (1-12), 4 bits for Year (Offset from 1997). | | CRC | 15 | Cyclic Redundancy Check. The script verifies this to ensure the CID is valid and not corrupted. |

The eMMC CID decoder is an essential utility for developers, digital forensics experts, and hardware repair technicians. It interprets the 128-bit Card Identification (CID) register found in every Embedded MultiMediaCard (eMMC) device, revealing critical manufacturing data that is otherwise hidden behind a wall of hexadecimal code. What is the eMMC CID Register?

The CID is a 16-byte (128-bit) unique identifier hardcoded into the eMMC's internal register. Unlike standard storage data, the CID is generally read-only and serves as the "fingerprint" of the chip. It contains technical metadata required for device authentication, firmware debugging, and hardware identification. Key Fields in the CID Structure

A standard eMMC CID decoder breaks down the hex string into the following fields, as defined by the JEDEC Standard: MultiCID Decoder

An eMMC CID (Card Identification) decoder is a critical tool for engineers, forensic analysts, and hardware enthusiasts working with embedded MultiMediaCards. The CID register is a 128-bit device-specific register that serves as the "digital birth certificate" of the flash memory chip. Decoding this hex string reveals the manufacturer, the age of the chip, and its technical specifications, which are vital for hardware validation and data recovery. The Structure of the CID Register emmc cid decoder

The 128-bit (16-byte) CID string is divided into several fixed fields defined by the JEDEC eMMC standard (e.g., JESD84-B51). A standard decoder breaks the raw hex into the following key components:

Manufacturer ID (MID): An 8-bit figure assigned by the SD-3C or JEDEC. For example, 0x15 usually indicates Samsung, while 0x13 points to Micron.

Device/BGA (CBX): Indicates whether the device is a BGA (Ball Grid Array) or another package type.

OEM/Application ID (OID): An 8-bit identifier that links the chip to a specific original equipment manufacturer or project.

Product Name (PNM): A 6-character ASCII string (48 bits). This is often the most readable part of the CID, showing names like "MAG2GA" or "KLMAG4."

Product Revision (PRV): A 1-byte field showing the hardware and firmware version of the chip.

Product Serial Number (PSN): A 32-bit unique number assigned to each individual unit. | Bit Position | Field Name | Size

Manufacturing Date (MDT): An 8-bit field representing the month and year the chip was produced.

CRC7 Checksum: A 7-bit checksum used to verify that the CID data has not been corrupted during transmission. Why Decoding Matters

The ability to interpret this data is more than a technical curiosity; it has significant practical applications:

Forensics and Security: In mobile forensics, the CID is used to verify the authenticity of a device. Because the CID is typically "read-only" and set at the factory, it helps investigators ensure that the flash storage hasn't been swapped or tampered with.

Supply Chain Validation: Manufacturers use decoders to verify that the chips they receive from suppliers match the required specifications and come from the correct production batches.

Hardware Hacking and Repair: For those performing "eMMC Pro" or "EasyJTAG" repairs, knowing the exact manufacturing date and revision can help in selecting the correct firmware (dump) to flash onto a bricked device.

Counterfeit Detection: Decoders can quickly identify "fake" chips where the external branding doesn't match the internal CID data. Technical Implementation Note: Some older eMMC versions have slight variations,

Most CID decoders are either small software utilities or web-based scripts. They work by taking a 32-character hexadecimal string and using bitwise shifts and masks to isolate the specific bits assigned to each field. For example, to find the Manufacturing Date, a decoder looks at bits [15:8] of the register, where 4 bits represent the month and 4 bits represent the year (offset from 2010 or 1997 depending on the specification version). Conclusion

The eMMC CID decoder is an essential bridge between raw hardware data and actionable information. By translating a cryptic string of hex digits into a detailed profile of a storage chip, it enables professionals to validate hardware, recover lost data, and maintain the integrity of embedded systems. As eMMC continues to be a staple in IoT devices, automotive systems, and budget electronics, the role of the CID decoder remains fundamental to hardware diagnostics.

Many routers, set-top boxes, and Android TV boxes require specific flash tools (MPTools). These tools often ask for the CID or require a "CID replacement" to restore a corrupted bootloader. Decoding helps match the correct firmware template.

Several free websites offer instant decoding. (Search "eMMC CID Decoder Online")

Example:
Input: fe014a4d4247474e036001cb0600e973
Decoded Output:

Even the best eMMC CID decoder has limits:

The CID is a 128-bit read-only register programmed into the eMMC during manufacturing. It contains unique data like:

Once you have the 32-character hexadecimal string, you need to decode it. You have several options: