Error detection circuit for microcomputer with monitoring timer - compares reference data set with state of internal node pref. in output range of microprogram memory

摘要

An internal state subject to variation during operation of the microcomputer is monitored by a comparator (202) connected to an internal node (201). A counter (203) measures a time interval related to a program execution period. An output unit (204) produces and transmits an error detection signal (220) on the basis of a predetermined condition, indicating that a special internal state (output from the microprogram store) used in normal operation as a reference data set is not attained within the time limit. ADVANTAGE - Error propagation is prevented anddetection time shortened in a reduced hardware structure.