On some series of the MSP430, as we all know, there is a chip-series-unique serial number that can made from the lot/wafer ID plus the die X & Y positions - a total of 8 bytes.
How are the X & Y positions & lot/wafer ID (and the other die-specific data) changed for each die - the masks can't be changed easily, so I would assume that some sort of fusible link was used that is programmed in after testing and before its sawn into individual die... are they fusible links or some other mechanism? e.g. the DS2401 uses a laser-programmed ROM....
Thanks