A central processing unit (CPU) repeatedly interrupts execution of software to save the CPU state, i.e. contents of various storage elements internal to the CPU, until an error occurs during the execution. On occurrence of the error, the CPU once again saves state and only then passes control to a handler...http://www.google.com.au/patents/US6202174?utm_source=gb-gplus-sharePatent US6202174 - Method for identifying and correcting errors in a central processing unit
