Memory device in mobile phone

A memory device for a mobile phone is provided. The memory device includes a flash memory for storing program data and user data; an interface circuit configured for interfacing the flash memory to a microprocessor; a first memory for copying the program data of the flash memory; and a second memory for executing the program data of the first memory wherein the first and second memories are independent memories. The flash memory is a NAND-type flash memory and the interface circuit is an application-specific integrated circuit (ASIC) including a read-only memory (ROM) for storing program codes and an error correction circuit. Additionally, the first and second memories are preferably random-access memories (RAM). By utilizing a NAND-type flash memory in place of a conventional NOR-type flash memory, the memory device can achieve a larger storage capacity at a lower cost.