A Scalable Dependability Scheme for Routing Fabric of SRAM-Based Reconfigurable Devices

With the continual scaling of feature size, system failure due to soft errors is getting more frequent in CMOS technology. Soft errors have particularly severe effects in static random-access memory (SRAM)-based reconfigurable devices (SRDs) since an error in SRD configuration bits can permanently change the functionality of the system. Since interconnect resources are the dominant contributor to the overall configuration memory upsets in SRD-based designs, the system failure rate can be significantly reduced by mitigating soft errors in routing fabric. This paper first presents a comprehensive analysis of SRD switch box susceptibility to short and open faults. Based on this analysis, we present a dependable routing fabric by efficiently employing asymmetric SRAM cells in configuration memory of SRDs. The proposed scheme is highly scalable and capable of achieving any desired level of dependability. In the proposed scheme, we also present a fault masking mechanism to mitigate the effect of soft errors in the routing circuitry. A routing algorithm is also proposed to take the advantage of the proposed routing fabric. Experimental results over the Microelectronics Center of North Carolina benchmarks show that the proposed scheme can mitigate both single and multiple event upsets in the routing fabric and can reduce system failure rate orders of magnitude as compared with the conventional protection techniques.