What is on the chip?
On Micron’s small BGA memory packages, a five-character code is printed instead of the full part number, for example D9XPZ. The code itself tells you nothing: not the product family, not the type, not the capacity. You only learn what it means by looking it up in Micron’s FBGA decoder.
Looked up, D9XPZ resolves to part number MT62F768M64D4BG-031 WT:A. According to the product page this is LPDDR5 RAM organised as 768M × 64 bit, which is 48 gigabit. Divided by eight, that is 6 GB. So you learn that the small black chip in your hand is 6 GB of RAM from the manufacturer’s document, not from the five letters on it.
Other manufacturers
Samsung and SK hynix usually print the full part number. Capacity still is not written out; it is encoded in the number, and you find its meaning in the manufacturer’s catalogue. Micron uses the same short-code system on packages that combine RAM and storage.
| Marking on the chip | Maker | According to the document | Source |
|---|---|---|---|
| D9XPZ | Micron | 6 GB LPDDR5 RAM (MT62F768M64D4BG-031 WT:A) | Micron FBGA decoder |
| JZ177 | Micron | 64 GB UFS + 4 GB RAM in one package (MT29VZZZAD8FQFSL) | Micron FBGA decoder, TN-29-85 Rev E |
| PS128 | SpecTek (Micron) | 8 GB RAM (SM2G32Z32MD4DNQ) | SpecTek Part Marking Decoder |
| K3RG2G20CA-MGCJ | Samsung | 4 GB mobile RAM | Samsung 1H 2017 Product Selection Guide, p. 8 |
| H9HKNNNDGUMUBR-NMH | SK hynix | 3 GB mobile RAM | SK hynix Q2 2017 Mobile Memory Databook, p. 2 |
| EMMC08G-ML36 | Kingston | 8 GB eMMC storage | Kingston eMMC flyer 2021, p. 2 |
Bits or bytes?
Manufacturer documents usually give density in gigabits (Gb). Phone and scrap trading talk in gigabytes (GB). The difference is a factor of eight. That one lowercase letter may also explain some errors in chip code tables; we look at that in a separate note.
How BoardVision handles it
BoardVision reads the text on the chip from the camera or a photo, on the device itself. It looks the code up in a reference list of 1,189 rows, 524 of which are backed by a manufacturer document. Capacity is shown only when the code is in the list. When it is not, the app says “no match” and does not guess.
In the first real photos (10 October 2026), three chip codes were read character for character. None of the three was in the list, so the app showed no match. A faded fourth code could not be read.
Limits
- Reading accuracy with a real camera has not been measured yet, so we give no rate.
- BoardVision does not test a chip electrically and does not prove that a chip is genuine. The marking tells you what the chip claims to be.
- The iOS and Android versions are in development and not in the app stores yet. The version we use today is an internal macOS prototype.