stm32 /stm32h5 /STM32H573 /FLASH /FLASH_NSOBKCFGR

OBKCFGR lock option configuration bit This bit locks the FLASH_NSOBKCFGR register. The correct write sequence to FLASH_NSOBKKEYR register unlocks this bit. If a wrong sequence is executed, or if the unlock sequence to FLASH_NSOBKKEYR 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_NSOBKCFGR register unlocked

1 (B_0x1): FLASH_NSOBKCFGR 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 and192 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 (OBKERR) 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 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. 0x01 means that only the first OBK data (128 bits) is copied from current to alternate OBK sector 0x02 means that the two first OBK data is copied

0 (B_0x00): means that no OBK is copied from current to alternate OBK sector during SWAP operation.

511 (B_0x1FF): means that all OBK data (511) is copied