Testing method

Abstract

Abstract PURPOSE: To make it possible to test easily logic units arranged on a substrate by providing either an auxiliary path or auxiliary circuit part which allows signals to by-pass a main circuit part realizing a function at which logic units aim. CONSTITUTION: On substrate 11, the logic circuit is composed of integrated-circuit chips IC 1 to IC 6 , and IC 1 to IC 4 and IC 6 have main circuit part 12 which realizes the function they aim at. Besides main circuit 12, IC 5 has auxiliary path 13 and selector circuit 14 for the by-pass of the main circuit part and according to the logical value of input C 1 , either output of main circuit part 12 or auxiliary path 13 is selected by selector circuit part 14 and then outputted. A test input is applied to inputs a1, b1, d1 and e1 of substrate 11 and a selective input to input c1, so that the test can be exercised by making checks on outputs f1 to h1 of substrate 11. COPYRIGHT: (C)1980,JPO&Japio

Inventors

• 👤 Yuichi Oka
• 👤 Yoshimitsu Takiguchi

Bibliographic Details