Fuse selectable timing signals for internal signal generators

Switching circuits controlled by a fuse that can be blown after testing the DRAM part select the timing signals coupled from a binary counter to internal signal generator circuits. The internal Circuits control self refresh in this embodiment. The decision to leave the fuse intact or blow the fuse rests on the test results obtained from each part and can vary depending upon maturity of the manufacturing process, the pause test results obtained and whether a low power part is desired. The fuse is affected after fabrication of the chip and at the same time as other fuses used for redundancy. This provides another degree of freedom in the manufacture of integrated circuits.