Architecture with multi-instance redundancy implementation

Abstract

A semiconductor memory architecture for embedded memory instances having redundancy. A fuse box register is provided outside the memory macro associated with the memory instances. The memory instances are daisy-chained to the fuse box register containing a plurality of fuses used for storing fuse data associated with the defective rows and columns of main memory. During power-up or after blowing the fuses, the contents of the fuses (i.e., fuse data) are transferred to a plurality of volatile redundancy scan flip-flops. The fuse box is then deactivated to eliminate quiescent current through the fuses. The redundancy scan flip-flops, connected in a scan chain, are located inside the fuse box as well as the memory instances. During the shifting mode of operation, the fuse contents are scanned into individual flip-flops, organized as scan registers for row redundancy and column redundancy, of the memory instances. Redundant elements are pre-tested by bypassing the fuses and directly scanning in arbitrary patterns into the redundancy scan flip-flops (override mode operation). The contents of row redundancy scan register (i.e., faulty wordline address information) are compared with an incoming wordline address and if there is a match found, the primary wordline or wordlines are de-selected and the redundant wordline or wordlines are selected.