US Patent RE41880 Semiconductor memory device

A semiconductor memory device includes (a) a plurality of reference cells, (b) a plurality of memory cells, data stored in a selected reference cell among the reference cells being compared to data stored in a selected memory cell among the memory cells, (c) an address transition detector for detecting transition in input of addresses by which a memory cell is selected among the memory cells, and transmitting an address transition detecting signal indicative of the detected transition, (d) a counter for counting the address transition detecting signals, and (e) a reference cell decoder for selecting a reference cell among the reference cells in accordance with an output transmitted from the counter.