The fault location and reconfigurable designs of Ripple Carry (RC) adders and Carry Save (CS) multipliers are studied in this thesis. The proposed designs can locate a faulty cell and reconfigure the faulty array to tolerate the faulty cell. Laser programming technique is used for fault location and reconfiguration. The key idea employed in the proposed methods is to perform diagnosis and reconfiguration at the same time. Appropriate fuses are programmed to locate a faulty cell, and the programmed fuses are also used for reconfiguration. This leads to small area overhead, and hence, substantial improvement in yield. Experimental results show that the yield enhancement of reconfigurable RC adders and CS multipliers is substantial compared with that of original RC adders and CS multipliers, respectively. / Master of Science