Feasibility of software-based repair for program memories

In this paper we evaluate the feasibility of software-based repair for program (NOR flash) memories in tiny embedded systems. Often, in such systems, it is very typical that not the full memory area is used by the application. This paper proposes a software-based self-repair for program memories which utilizes this inherently available redundancy. Our techniques combine application adaptation in respect to faulty memory words and protection of the adapted application with error-correcting code. With our approach we address post-production memory faults and retention- and radiation-related memory faults which can occur in the field. The evaluation of our repair mechanisms was based on the results from post-production and after burn-in tests performed on real 32 and 64 KByte flash memory devices.