ST STM32F4

Option byte programming

The STM32F4 series devices provide some option bytes which allow some "permanent" configuration as well as readout protection for the device. Unfortunately, the option bytes become effective immediately when programmed. This means when enabling the read protection of the device via option bytes, the programmer will immediately lose the access to the flash, without any possibility to verify the complete flash operation. Therefore, the option bytes cannot be programmed as part of the flash image. via J-Flash