Exception handling processor.

摘要

There is disclosed an improved processor having improved exception handling capability. The processor processes instructions in order through a plurality of serial stages. A first set of registers continuously tracks each instruction as they are advanced from stage to stage. An exception handler processes first level exception conditions and precludes updating of the first set of registers when it processes first level exception conditions to permit the processor to restart at the point of a first level exception condition. A second set of registers continuously trans the instruction in tandem with the first set of registers, but is updatable during the processing of first level exception conditions by the exception handler. Monitor means processes second level exception conditions occurring in the exception handler and precludes the second set of registers from being updated when it processes the second level exception conditions to permit the exception handler to restart from the point of the occurrence of a second level exception condition.