| 摘要 |
PURPOSE:To attain restoration from the runaway state by providing a pulse output instruction in a program execution loop and using a circuit detecting that the pulse output is stopped so as to detect surely the program runaway. CONSTITUTION:If a runaway of a program under execution of a main program takes place, an idle loop is not executed or interruption remains inhibited or not permitted. Then no pulse train is outputted from a flip-flop 1 and when a setting time is elapsed, an output of a monostable multivibrator 2 goes to 'L' level and an INTO interruption is generated. If the INTO interruption takes place at a non-maskable terminal (INTO terminal) is generated, the initial setting of ports P0, P1, P2, P4 is executed, a display LED is deriven for error display thereby displaying program runaway. When number of times of runaway exceeds a prescribed limit, a HALT instruction is executed to stop the program.
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