Fault and Soft Error Tolerant Delay-Locked Loop

We present in this paper the first fault and soft error tolerant Delay-Locked Loop (DLL) design, useful for the clock synchronization in a chip incorporating heterogeneous functional dies. In this robust DLL design, we introduce a powerful timing correction scheme to remedy the timing shortfall in a naïve Triple-Module Redundancy (TMR) architecture. Post-layout simulation results using a 90nm CMOS process is used to verify the performance of this design. In addition to the tolerance of randomly injected faults or soft errors, the Maximum Phase-Error can be improved tremendously from 117ps to just 17ps by the proposed timing correction scheme.