FLASH_MassErase() function

The device voltage range which defines the erase parallelism. This parameter can be one of the following values: @arg FLASH_VOLTAGE_RANGE_1: when the device voltage range is 1.8V to 2.1V, the operation will be done by byte (8-bit) @arg FLASH_VOLTAGE_RANGE_2: when the device voltage range is 2.1V to 2.7V, the operation will be done by half word (16-bit) @arg FLASH_VOLTAGE_RANGE_3: when the device voltage range is 2.7V to 3.6V, the operation will be done by word (32-bit) @arg FLASH_VOLTAGE_RANGE_4: when the device voltage range is 2.7V to 3.6V + External Vpp, the operation will be done by double word (64-bit)

Banks to be erased This parameter can be one of the following values: @arg FLASH_BANK_1: Bank1 to be erased @arg FLASH_BANK_2: Bank2 to be erased @arg FLASH_BANK_BOTH: Bank1 and Bank2 to be erased