A flash memory device includes multiple memory blocks, a decoder configured to select at least one of the memory blocks in response to block select signals, a controller configured to generate the block select signals in response to a block address and to generate a flag signal when the block address corresponds to a bad block, and an output buffer configured to output fixed data in response to the flag signal indicating that the block address corresponds to the bad block. When the block address corresponds to a bad block, the controller generates the block select signals to cause the decoder to interrupt selection of a memory block corresponding to the block address.