Reprogrammable logic devices, such as FPGAs (field programmable gate arrays), are devices that are configurable to perform a certain logic function. Such devices generally comprise millions of static random access memory (SRAM) cells, each storing configuration data for configuring the logic function to be implemented.
Radiation, for example in the form of cosmic particles, can create errors in electronic devices, and are particularly problematic in the case of reprogrammable logic devices. Indeed the radiation may cause errors not only in the data that is being processed, but also in the configuration data, resulting in a change of the logic function implemented by the circuit.
US patent publication U.S. Pat. No. 7,764,081 proposes a solution for protecting a reprogrammable logic device from errors due to single event upsets (SEUs). According to this solution, the SRAM cells that store the configuration data in the reprogrammable logic device are replaced by DRAM (dynamic random access memory) cells, which are periodically refreshed from a PROM (programmable read-only memory).
However, a problem with the solution proposed by U.S. Pat. No. 7,764,081 is that it is relatively complex and energy consuming. There is thus a need in the art for a simple and low energy consuming solution for protecting a reprogrammable logic device from errors caused by radiation.