US Patent 7170804 Test mode for detecting a floating word line

Devices and methods that allow floating word lines in memory arrays to be detected are provided. By driving local word lines from each side with divided drive lines, local word lines on one side of the memory array may be set to an predetermined voltage level (e.g., an intermediate voltage level between VPP and VNWLL). After disconnecting the local word lines on the one side, memory cells on the other side may be tested for read failures, which may indicate floating word lines on the one side.