1. Field
Example embodiments relate to semiconductor memory devices and, particularly, to a user device including a flash memory device storing an index and an access method thereof.
2. Description
A semiconductor memory device is a memory device capable of storing data and retrieving target data by reading stored data, as needed. Semiconductor memory devices may be classified into volatile memory devices and nonvolatile memory devices.
Volatile semiconductor devices lose their data when their power supplies are interrupted, while nonvolatile memory devices retain their stored data even when their power supplies are interrupted. Volatile memory devices include static random access memories (SRAM), dynamic random access memories (DRAM), and synchronous dynamic random access memories (SDRAM). Nonvolatile memory devices include read only memories (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically EPROM (EEPROM), flash memories, phase-changeable random access memories (PRAM), magnetic random access memories (MRAM), and ferroelectric random access memories (FRAM). Flash memories are classified into two types, i.e., NOR-type flash memories and NAND-type flash memories.