A single event upset ( SEU ) is a change of state caused by a low-energy ions or electro-magnetic or nuclear radiation or any other kind of interferences that can reach ( called `` strike '' ) a sensitive node in a micro-electronic device , such as in a microprocessor , semiconductor memory , or power transistors . A single event upset ( SEU ) is a change of state caused by ions or electro-magnetic radiation striking a sensitive node in a micro-electronic device , such as in a microprocessor , semiconductor memory , or power transistors .