FLASH MEMORY DEVICE CAPABLE OF PERFORMING MULTI-BIT AND SINGLE-BIT PROGRAM OPERATIONS WITH A SINGLE PAGE BUFFER STRUCTURE

摘要

A flash memory device performing multi-bit and single-bit program operations with a single page buffer is provided to perform multi-bit program/read operation and single-bit program/read operation, cache program operation and page copy-back operation by the single page buffer structure. In a flash memory device having memory cells in which plural bit lines and plural word lines are arranged, a sensing node is connected to a selected bit line. A sensing circuit(440) selectively transfers data of the sensing node to a common node. A first register(410) is connected to the sensing node and the common node, and latches data on the common node. A second register(420) latches data of the common node through a switch(470) during initial read period of multi-bit program operation. And a discharge circuit(460) discharges the sensing node according to the data latched in the second register during the initial read operation, during first verification read period of the multi-bit program operation.