FLASH control key register
CUKEY | Control unlock key Following values must be written to FLASH_KEYR consecutively to unlock FLASH_CR register: 1st key = 0x4567 0123 2nd key = 0xCDEF 89AB Reads to this register returns zero. If above sequence is wrong or performed twice, the FLASH_CR register is locked until the next system reset, and access to it generates a bus error. |