DocID15687 Rev 5

21/29

PM0059

Flash memory interface

28

2.8.2

Flash key register (FLASH_KEYR)

The Flash key register is used to allow access to the Flash control register and so, to allow

program and erase operations.

Address offset: 0x04

Reset value: 0x0000 0000

Access: no wait state, word access

2.8.3

Flash option key register (FLASH_OPTKEYR)

The Flash option key register is used to allow program and erase operations in the user

configuration sector.

Address offset: 0x08

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

KEY[31:16]

wwww

ww

w

w

w

w

w

w

w

w

w

w

15

14

13

12

11

10

9

8

76

5432

1

0

KEY[15:0]

wwww

ww

w

w

w

w

w

w

w

w

w

w

Bits 31:0 FKEYR: FPEC key

The following values must be programmed consecutively to unlock the FLASH_CR register

and allow programming/erasing it:

a)

KEY1 = 0x45670123

b)

KEY2 = 0xCDEF89AB

31

30

29

28

27

26

25

24

23

22

21

20

19

18

17

16

OPTKEYR[31:16

wwww

ww

w

w

w

w

w

w

w

w

w

w

15

14

13

12

11

10

9

8

7

6

5

4

3

2

1

0

OPTKEYR[15:0]

wwww

ww

w

w

w

w

w

w

w

w

w

w

Bits 31:0 OPTKEYR: Option byte key

The following values must be programmed consecutively to unlock the FLASH_OPTCR

register and allow programming it:

a)

OPTKEY1 = 0x08192A3B

b)

OPTKEY2 = 0x4C5D6E7F