Patent ID: 7499358

Claim:
A method of controlling a reference current generation circuit that generates a predetermined reference current which is used by read circuitry during a read operation to data a data state of one or more memory cells, wherein the reference current generation circuit includes (i) a plurality of reference cell circuits including a first reference cell circuit and a second reference cell circuit, each reference cell circuit including a plurality of reference cells, and (ii) a reference current driver, the method comprising: programming at least one of the reference cells of the first reference cell circuit to one of a plurality of predetermined states; programming at least one of the reference cells of the second reference cell circuit to one of a plurality of predetermined states, wherein a majority of the reference cells of the reference cell circuits is programmed to a second state and a minority of the reference cells of the reference cell circuits is programmed to a first state; and outputting the predetermined reference current, wherein the amount of the predetermined reference current is associated with the programmed states of the reference cells of the plurality of reference cell circuits.