In-Field Test for Permanent Faults in FIFO Buffers of NoC Routers

Abstract— An on-line transparent test technique for detection of latent hard faults which develop in first input first-output buffers of routers during field operation of NoC. The technique involves repeating tests periodically to prevent accumulation of faults. A prototype implementation of the proposed test algorithm has been integrated into the router-channel interface and on-line test has been performed with synthetic self-similar data traffic. The performance of the NoC after addition of the test circuit has been investigated in terms of throughput while the area overhead has been studied by synthesizing the test hardware. In addition, an on-line test technique for the routing logic has been proposed which considers utilizing the header flits of the data traffic movement in transporting the test patterns. A transparent SOA-MATS ++ test generation algorithm has proposed targeting in-field permanent faults developed in SRAM-based FIFO memories and it has been utilized to perform online and periodic test of FIFO memory present within the routers of the NoC. In addition, we have also proposed an online test technique for the routing logic that is performed simultaneously with the test of buffers. The proposal involves two ways of utilizing the unused portion of the header flits of the incoming data packets in transporting the test patterns. First, deterministic test patterns for the routing logic generated by Tetramax are placed in the unused fields of the header flit and are transported during the normal cycle. < final year projects >