docs: def get_flash_crypt_config(self):
          """ bit 3 in efuse_rd_disable[3:0] is mapped to flash_crypt_config
          this bit is at position 19 in EFUSE_BLK0_RDATA0_REG """
          word0 = self.read_efuse(0)
          rd_disable = (word0 >> 19) & 0x1
  
          if rd_disable == 0:
              """ we can read the flash_crypt_config efuse value
              so go & read it (EFUSE_BLK0_RDATA5_REG[31:28]) """
              word5 = self.read_efuse(5)
              word5 = (word5 >> 28) & 0xF
              return word5
          else:
              # if read of the efuse is disabled we assume it is set correctly
              return 0xF