Multiple modes of operation in a cross point array. The invention is a cross
point array that uses a read voltage across a conductive array line pair during
a read mode. The read voltage produces a read current that is indicative of a first
program state when the read current is at a first level and indicative of a second
program state when the read current is at a second level. The read current is ineffective
to produce a change in program state. A first voltage pulse is used during a first
write mode if a change from a second program state to a first program state is
desired. A second voltage pulse is used during a second write mode if a change
from the first program state to the second program state is desired.
