An electronic device may include a set of two or more scan chains and a buffer chain. Each of the scan chains includes a sequence of stateful elements connected in series, and each of the scan chains is arranged to hold a string having a length identical to the length of the respective scan chain. The strings of the scan chains are shifted in parallel from the scan chains into the memory unit and back from the memory unit into the respective scan chains. The store operation and the restore operation each include at least N0 elementary downstream shift operations. The set of scan chains includes a short chain and a detour chain, and the short chain has a length N1 which is shorter than N0. The set of scan chains further includes a buffer chain. The output end of the short chain is coupled to an input end of the buffer chain. The buffer chain is provided at least partly by the detour chain.