Hello, we have boards with the MCU STM32F746. This works normally but in two cases we had a problem with the option bytes. Several values were changed and now we can't remove the protection.
The first board we tried several times to change level protection of 1 to 0, and finally we done it.
In the second board, at the moment it's not possible for us. The level is the 1 and we don't undestand why we can't go back to level 0.
This is the configuration of the options bytes
OPTION BYTES BANK: 0
Read Out Protection:
RDP : 0xFF (Level 1, read protection of memories)
BOR Level:
BOR_LEV : 0x3 (BOR off, POR/PDR reset threshold level is applied)
User Configuration:
IWDG_STOP : 0x1 (IWDG counter active in stop mode)
IWDG_STDBY : 0x1 (IWDG counter active in standby mode)
WWDG_SW : 0x0 (Hardware window watchdog)
IWDG_SW : 0x0 (Hardware independant watchdog)
nRST_STOP : 0x1 (No reset generated)
nRST_STDBY : 0x1 (No reset generated)
Boot address Option Bytes:
BOOT_ADD0 : 0xEFBB (0x3BEEC000)
BOOT_ADD1 : 0xF5EF (0x3D7BC000)
Write Protection:
nWRP0 : 0x1 (Write protection not active on this sector)
nWRP1 : 0x1 (Write protection not active on this sector)
nWRP2 : 0x1 (Write protection not active on this sector)
nWRP3 : 0x1 (Write protection not active on this sector)
nWRP4 : 0x1 (Write protection not active on this sector)
nWRP5 : 0x1 (Write protection not active on this sector)
nWRP6 : 0x1 (Write protection not active on this sector)
nWRP7 : 0x1 (Write protection not active on this sector)
And when we try to remove the protection this happens:
SWD freq : 4000 KHz
Connect mode: Under Reset
Reset mode : Hardware reset
Device ID : 0x449
Device name : STM32F74x/STM32F75x
Flash size : 63,999 MBytes
Device type : MCU
Device CPU : Cortex-M7
Disabling memory Read Protection...
Error: Disabling memory Read Protection failed
Regarding the power supply, it's stable.
Anyone know who we can solve it?
Thanks & best regards
