| 摘要 |
PURPOSE:To make it possible to point out a fault location rapidly by making it possible to observe independently abnormality of each part of a unit by using a small number of observation terminals for a fault diagnosis, by providing an input- output signal compressing circuit to each physically-divided unit of a unit to be diagnosed. CONSTITUTION:Fault diagnostic unit 100 sets one of a group of package selective signals 140 to logic ''1'', which is supplied to unit 200 to be diagnosed, and after a package to be diagnosed is selected, the contents of input signal observation bus 120 and output signal observation bus 130 are compared, clock by clock, with an expected value stored in unit 100 synchronizing with the execution of a fault diagnostic program. In this operation, unit 100 can count clocks of unit 200. When the contents of the observation buses are judged to disagree with the expected value, a count value showing the order of a clock when the disagreement has been detected and data indicating which bus has the disagreement are stored in unit 100. On the end of the program, unit 100 selects the other package by package selective signal 140 and starts the program again. |
