Disclosed is a semiconductor memory device, in which the refresh period of
a fail cell or cells is set so as to be shorter than that of the normal
cells, comprises a control circuit for exercising control in such a
manner that, if, when refreshing the cell of a first address, generated
responsive to a refresh command, with an input control signal being of a
first value, a second address, differing as to the value of a
predetermined bit from the first address, is determined to correspond to
a fail cell, based on the information ore-programmed in a refresh
redundant ROM, the cell of the second address is refreshed, and also in
such a manner that, if, with the input control signal of a second value,
the second address, differing as to the value of a predetermined bit from
the first address, is determined to correspond to a fail cell, based on
the predetermined information, only the cell of the second address is
refreshed, without refreshing the cell of the first address, generated
responsive to the refresh command.