stm32 /stm32h5 /STM32H563 /FLASH /FLASH_SECOBKCFGR

OBKCFGR lock option configuration bit This bit locks the FLASH_OBKCFGR register. The correct write sequence to FLASH_SECOBKKEYR register unlocks this bit. If a wrong sequence is executed, or if the unlock sequence to FLASH_SECOBKKEYR is performed twice, this bit remains locked until the next system reset. LOCK can be set by programming it to 1. When set to 1, a new unlock sequence is mandatory to unlock it. When LOCK changes from 0 to 1, the other bits of FLASH_NSCR register do not change.

0 (B_0x0): FLASH_OBKCFGR register unlocked

1 (B_0x1): FLASH_OBKCFGR register locked

OBK swap sector request bit When set, all the OBKs which have not been updated in the alternate sector is copied from current sector to alternate one. The SWAP_OFFSET value must be a certain minimum value in order for the swap to be launched in OBK-HDPLdifferent 0. Minimum value is 16 for OBK-HDPL=1, 144 for OBK-HDPL=2 and 192 for OBK-HDPL=3.

0 (B_0x0): no swap requested

1 (B_0x1): launch the sector swap

alternate sector bit This bit must not change while filling the write buffer, otherwise an error is generated

0 (B_0x0): current OBK sector is mapped to OBK address range for access

1 (B_0x1): alternate OBK sector is mapped to OBK address range for access

alternate sector erase bit When ALT_SECT bit is set, use this bit to generate an erase command for the OBK alternate sector. It is set only by Software and cleared when the OBK swap operation is completed or an error occurs (PGSERR). It is reseted at the same time as the BUSY bit.

0 (B_0x0): do not touch OBK sector

1 (B_0x1): erase the alternate OBK sector

key index (offset /16 bits) pointing for next swap.

0 (B_0x0): no OBK is copied from current to alternate OBK sector during SWAP operation.

1 (B_0x1): only the first OBK data (128 bits) is copied from current to alternate OBK sector

2 (B_0x2): the two first OBK data are copied

511 (B_0x1FF): that the 511 first OBK data are copied