1.  Technical Field
The present invention relates to a semiconductor memory device, a memory system including the same, and an operation method thereof. 
2.  Related Art
A semiconductor memory device is a memory device implemented by using a semiconductor, such as silicon (Si), germanium (Ge), gallium arsenide (GaAs), an indium phosphide (InP).  The semiconductor memory device is generally classified into a volatile memory device and a nonvolatile memory device. 
The volatile memory device is a memory device in which stored data dissipates when a power supply is cut.  The volatile memory device includes a Static RAM (SRAM), a Dynamic RAM (DRAM), a Synchronous DRAM (SDRAM), and the like.  The nonvolatile memory device is a memory device in which stored data is maintained even though a power supply is cut.  The nonvolatile memory device includes a Read Only Memory (ROM), a Programmable ROM (PROM), an Electrically Programmable ROM (EPROM), an Electrically Erasable and Programmable ROM (EEPROM), a flash memory, a Phase-change RAM (PRAM), a Magnetic RAM (MRAM), a Resistive RAM (RRAM), a Ferroelectric RAM (FRAM), and the like.  The flash memory is generally divided into a NOR type and a NAND type.