Nonvolatile memory device with double hierarchical decoding

摘要

A flash-EEPROM memory array (30) comprises cells grouped together in sectors (31) and has both hierarchical row and hierarchical column decoding. Global word lines (35) are connected to word lines (36) in each sector through local row decoders (33). Global bit lines (42) are connected to local bit lines (43) through local column decoders (40). A global column decoder (41) and sense amplifiers (47) separate an upper half (30a) from a lower half (30b) of the memory array.