On self-healing digital system design

In recent years there has been a significant growth of interest in exploiting the principles of biological processes to create powerful methodologies for solving computational problems. This paper discusses how these features have been exploited in digital hardware design. It also introduces an architecture for implementing self-healing digital systems that is inspired by the antigen protection mechanism employed by the human immune system. In the proposed architecture, a spare cell is dedicated to replace one in a group of four functional cells. Once one of these four functional cells is found to be faulty, the spare cell is cloned as the faulty cell. This architecture is especially suitable for tolerating soft errors in functional cells or on interconnect lines. Another major advantage of this architecture is that the outputs of functional cells are connected to the inputs of other physically adjacent functional cells, thus making it appropriate for nanocomputing system design.