Nonvolatile memory device and method of programming a nonvolatile memory

Abstract

A nonvolatile memory device includes a memory block and a control circuit. The memory block includes cell strings. The control circuit controls a first program operation by dividing program data having threshold voltage distributions which have a plurality of states into a plurality of groups, discharging target bit-lines coupled to selected cell strings corresponding to the groups to a ground voltage during a bit-line set-up period of a program loop, discriminating a set-up timing of each of the target bit-lines based on target states of the groups during a first sub period, in which a program voltage and a program pass voltage are ramping and applying the program voltage with a signal pulse having a second target level to a selected word-line, while applying the program pass voltage having a first target level to unselected word-lines, during a second sub period.