uint8_t The FLASH BOR level: - OB_BOR_LEVEL3: Supply voltage ranges from 2.7 to 3.6 V - OB_BOR_LEVEL2: Supply voltage ranges from 2.4 to 2.7 V - OB_BOR_LEVEL1: Supply voltage ranges from 2.1 to 2.4 V - OB_BOR_OFF : Supply voltage ranges from 1.62 to 2.1 V