Patent ID: 6452838
Filing Date: 2002-09-17
Classification: G11C

Abstract:
A nonvolatile memory system comprising:a plurality of nonvolatile memories; and a controller, wherein each of said plurality of nonvolatile memories has a plurality of nonvolatile memory cells and a plurality of word lines each of which coupled to ones of said plurality of said nonvolatile memory cells; wherein each of said nonvolatile memory cells has a threshold voltage within one of a plurality of threshold voltage ranges, wherein said controller supplies a first operation command and a second operation command to at least one nonvolatile memory, wherein in an operation of said first operation command, said nonvolatile memory selects one of said word lines and supplies a first voltage to said selected word line during a first predetermined time, and wherein in an operation of said second operation command, said nonvolatile memory selects ones of said word lines and supplies said first voltage to said selected word line during a second predetermined time.