Device electronic signature
RM0090
DocID018909 Rev 11
39
Device electronic signature
The electronic signature is stored in the Flash memory area. It can be read using the
JTAG/SWD or the CPU. It contains factory-programmed identification data that allow the
user firmware or other external devices to automatically match its interface to the
characteristics of the STM32F4xx microcontrollers.
39.1
Unique device ID register (96 bits)
The unique device identifier is ideally suited:
•
for use as serial numbers (for example USB string serial numbers or other end
applications)
•
for use as security keys in order to increase the security of code in Flash memory while
using and combining this unique ID with software cryptographic primitives and
protocols before programming the internal Flash memory
•
to activate secure boot processes, etc.
The 96-bit unique device identifier provides a reference number which is unique for any
device and in any context. These bits can never be altered by the user.
The 96-bit unique device identifier can also be read in single bytes/half-words/words in
different ways and then be concatenated using a custom algorithm.
Base address: 0x1FFF 7A10
Address offset: 0x00
Read only = 0xXXXX XXXX where X is factory-programmed
Address offset: 0x04
Read only = 0xXXXX XXXX where X is factory-programmed
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10
9
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1
0
U_ID(31:0)
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Bits 31:0
U_ID
(31:0):
31:0 unique ID bits
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U_ID(63:48)
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15
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1
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U_ID(47:32)
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Bits 31:0
U_ID(63:32):
63:32 unique ID bits