A semiconductor memory device includes a memory string on a well, the memory string including a memory cell connected in series between first and second select transistors, a bit line and a source line respectively connected to the first and second select transistors, a well line connected to the well, first and second select lines respectively connected to gates of the first and second select transistors, a word line connected to a gate of the memory cell transistor, and a control circuit that performs a write operation on the first select transistor, the write operation including a pre-charge operation of the bit line, in which a first voltage is applied to the word line and the second select line, a second voltage higher than the first voltage to the source line and the well line, and a third voltage higher than the first voltage to the first select line.

Programming non-volatile memory includes applying a series of programming pulses to the memory cells as part of a coarse/fine programming process. Between programming pulses, memory cells in the coarse phase are verified for a coarse phase verify level for a target data state and memory cells in the fine phase are verified for a fine phase verify level for the target data state, both in response to a single reference voltage applied on a common word line. For a memory cell in the coarse phase that has been verified to have reached the coarse phase verify level, the memory cell will be temporarily inhibited from programming for a next programming pulse and switched to the fine phase. For a memory cell in the fine phase that has been verified to have reached the fine phase verify level, the memory cell will be inhibited from further programming.

A method of programming a memory system includes: reading a target page included in a selected memory block in response to a program request when at least one of the pages included in the selected memory block contains data; and performing a program for the target page when, among the data bits included in the data read from the target page, the number of data bits having a first logic value is equal to or less than a preset value.

Memory controllers, memory devices, memory systems and operation methods are provided. A memory controller is to: find, in input data, a binary code to be replaced corresponding to a preset programming level to be replaced, the input data is to be written into a memory cell; and substitute the binary code to be replaced in the input data with a replacement binary code corresponding to a preset replacement programming level, and generate a replacement identifier linking a memory address corresponding to the replacement binary code. The quantity of states is reduced by modifying a data encoding mode of the memory controller to help shorten programming duration of the memory device and reduce disturbance.

An operation method of a memory device for programming memory cells to a plurality of program states includes providing a series of program pulses to selected memory cells, performing a first verification operation of verifying a target program state among the plurality of program states, performing, when the first verification operation is passed, a second verification operation of detecting fail cells among the selected memory cells to determine if these memory cells have been overprogrammed. When the number of detected fail cells is greater than or equal to a reference value, the program operation may be terminated for that location and the data may be written to another location.