Interruption of data processing program to perform auxiliary program - using interrupt device with two interrupt modes which interact and mutually monitor to ensure interruption

摘要

An interruption device (2) connected to a data processing system (1) via an internal data and address bus uses two different interruption modes (UA1, UA2) which cannot both be changed simultaneously by a single processor instruction to prevent access to both interrupt routines. The two interrupt modes interact and monitor each other so that the interruption process is ensured. The current state of the interrupt device is made accessible to the data processing system via one or more read/write registers. USE/ADVANTAGE - For maximising reliability of interruption of programs running in data processing systems to allow auxiliary programs to run.