MEMORY, MEMORY SYSTEM, AND OPERATION METHOD OF MEMORY SYSTEM

A memory includes: a non-volatile memory suitable for storing a defect address; a register suitable for receiving and storing the defect address from the non-volatile memory during a boot-up operation, and receiving and storing an address that is input from an exterior during a register access operation; a comparison circuit suitable for comparing the address stored in the register with an address that is input from the exterior to produce a comparison result; redundant memory cells that are accessed according to the comparison result of the comparison circuit and a redundancy activation bit; and normal memory cells that are accessed according to the comparison result of the comparison circuit and the redundancy activation bit.