Patent ID: 7248528

Claim:
A refresh control method of a semiconductor memory device which controls a self-refresh operation to hold data in a memory array having a plurality of memory cells disposed at intersections of word lines corresponding to row addresses and bit lines corresponding to column addresses, comprising: a step for dividing said memory array into a holding area used as a copy source which includes memory cells on a predetermined number of word lines, and a copy area used as a copy destination which includes memory cells on word lines to which entire data of said holding area is to be copied, a step for executing copy operation in which data of each memory cell of said holding area is copied to one or more memory cells in said copy area on the same bit line or the same pair of bit lines before executing said self-refresh operation, and a step for executing said self-refresh operation in which a row address of said holding area is designated and a corresponding word line is selected and driven, and at the same time, one or more word lines in said copy area corresponding to said selected word line are selected and driven.