On-Line Reconfigurable XGFT Network-on-Chip Designed for Improving the Fault-Tolerance and Manufacturability of the MPSoC Chips

Large System-on-Chip (SoC) circuits will contain an increasing number of processors which will communicate with each other across Networks-on-Chip (NOC). The faulty processors could be replaced with faultless ones, whereas only a single defect in the NOC can make the whole chip unusable. Therefore, the fault-tolerance of the NOC is a crucial component of the fault-tolerance and manufacturability of the SoCs. This paper presents a fault-tolerant extended generalized fat tree (XGFT) NOC developed for future multi-processor SoCs (MPSoC). Its fault-tolerance is improved with a new version of fault-diagnosis-and-repair (FDAR) system, which makes it possible to diagnose and repair the NOC on-line. It detects such static, dynamic and transient faults which block packets or produce bit errors, and reconfigures the faulty switches to operate correctly. Processors can also use it for reconfiguring the faulty switch nodes after the faults are located with other test methods. Simulation and synthesis results show that slightly defected XGFTs are able to achieve good performance after they are repaired with the FDAR while the costs of the FDAR remain tolerable