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There is no serial number on the individual die, but TSMC has very unique test lines on the chip that would easily identify if it was in fact made at TSMC.
by j_walter 2y ago
There is no serial number on the individual die, but TSMC has very unique test lines on the chip that would easily identify if it was in fact made at TSMC.
- 0xTJ 2y agoIs it indicated somewhere in this article, or somewhere else, that the dies are not programmed with a unique serial while still as part of a whole wafer?
- j_walter 2y agoNo, but any programming that would occur with identifiable information would occur after the wafer is cut and packaged. Generally this would be after delivery to TSMC's customer.
- 0xTJ 2y agoThere isn't any indication here one way or the other, but some the unique IDs of some devices (Microchip unique MAC chips) are documented as being programmed as a wafer, before being diced (as justification for them not being in serial order on a reel, that they may be shuffled from wafer to packaging).
- wiml 2y agoBy default I'd assume most chips don't get serialized (their package may have a date/lot code). The article doesn't say what the chip is, so I don't think there's a reason to think that it's one of the types of chip that does usually get a unique ID.
- londons_explore 2y agoI don't have insider knowledge... But I could believe that there is no per-die serial number unless the customer wants one. It would be extra manufacturing steps, and require integration with the customers design. Due to the way lithography works, it isn't easy to make each die different. The usual way to put serial numbers into chips is with efuses, but not all chips have any efuses at all, and it would require collaboration with the customer to design a way that they be programmed and read (probably on a JTAG chain).
- ddingus 2y agoThey could burn the number in after the chip is made. Either one time fuses and some software, or via directed beam energy fusible or breakable links. Edit, yeah like the other comment suggested.