MODE VERIFICATION METHOD FOR BIDIRECTIONAL TERMINAL IN SCAN PATH

摘要

PURPOSE: To exactly verify a bidirectional input/output mode at a high speed in the course of scan operation. ;CONSTITUTION: In an initialization processing 2, an indefinite value is set to an input terminal varied at the time of scan shift operation, and a definite value is set to an input terminal which is not varied. In a definite value propagation processing 3, a newly generated definite value is propageted to a connecting destination. In an output value determination processing 4, an output value of an element is determined by only the definite value propageted to the input. In a decision processing 5 for generation of a new definite value, in the case there is an element in which a definite value is generated newly in the output by the output value determination processing 4, the processing advances to the definite value propagation processing 3, and when not, the processing advances to an input/output mode verification processing 6. In the input/output mode verification processing 6, whether an input/output mode switching signal of a bidirectional terminal is decided definitely or no is varified. In this case, it can be verified that the input/output mode of the bidirectional terminal can be verified without simulating a shift operation of a scan path and such a problem as a bus fight, etc., in not caused.;COPYRIGHT: (C)1993,JPO&Japio