Nonvolatile semiconductor memory having program verifying circuit

摘要

A nonvolatile semiconductor memory device according to the present invention includes an array of cell units, each cell unit including at least one memory transistor which has a floating gate and a control gate, the array being divided into a plurality of memory blocks each having a certain number of cell units. The nonvolatile semiconductor memory device operates in a program mode, a program verify mode and a read mode. A current source provides a predetermined electrical current to the bit lines during both data reading and programming modes, and a common data latch stores program data during a write operation, as well as senses and stores data when the nonvolatile memory device is operated in a data read mode and a program verify mode.