A Novel Low Overhead Fault Tolerant Kogge-Stone Adder Using Adaptive Clocking

— As the feature size of transistors gets smaller, fabricating them becomes challenging. Manufacturing process follows various corrective design-for-manufacturing (DFM) steps to avoid shorts/opens/bridges. However, it is not possible to completely eliminate the possibility of such defects. If spare units are not present to replace the defective parts, then such failures cause yield loss. In this paper, we present a fault tolerant technique to leverage the redundancy present in high speed regular circuits such as Kogge-Stone adder (KSA). Due to its regularity and speed, KSA is widely used in ALU design. In KSA, the carries are computed fast by computing them in parallel. Our technique is based on the fact that even and odd carries are mutually exclusive. Therefore, defect in even bit can only corrupt the even Sum outputs whereas the odd Sums are computed correctly (and vice versa). To efficiently utilize the above property of KSA in presence of defects, we perform addition in two- clo...

• Type: Conference
• Year: 2008
• Where: DATE
• Authors: Swaroop Ghosh, Patrick Ndai, Kaushik Roy
• Keywords: DATE 2008, Failures Cause Yield, Fault Tolerant Technique, Hardware, Various Corrective Design-for-manufacturing