ST STM32L4 5 Series - Flash Key Register (FLASH_KEYR); Flash Option Key Register (FLASH_OPTKEYR)

DocID024597 Rev 5 123/1830
RM0351 Embedded Flash memory (FLASH)
136
3.7.3 Flash key register (FLASH_KEYR)
Address offset: 0x08
Reset value: 0x0000 0000
Access: no wait state, word access
3.7.4 Flash option key register (FLASH_OPTKEYR)
Address offset: 0x0C
Reset value: 0x0000 0000
Access: no wait state, word access
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
KEYR[31:16]
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15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
KEYR[15:0]
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Bits 31:0 KEYR: Flash key
The following values must be written consecutively to unlock the FLACH_CR
register allowing flash programming/erasing operations:
KEY1: 0x4567 0123
KEY2: 0xCDEF 89AB
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
OPTKEYR[31:16]
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15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
OPTKEYR[15:0]
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Bits 31:0 OPTKEYR: Option byte key
The following values must be written consecutively to unlock the FLACH_OPTR
register allowing option byte programming/erasing operations:
KEY1: 0x0819 2A3B
KEY2: 0x4C5D 6E7F