STM32L031F6P7. Unique Device base address: 0x1FF8 0050 is always same. Serial trailer always 0000.

[Swapnil1]

we bought at Arrow, Date code 2142, COO:PH, CC:RHC. Debugger always shows:

[MM..1]

Try reading ref

[TDK · Accepted solution]

The first 64 bits of the UID field is at 0x1FF80050.

The last 32 bits of the UID field is at 1FF80064.

They are not contiguous. They last 32 bits are not shown in your figure.

[Swapnil1]

Thank you!