Method and apparatus for the testing of connections of an electronic apparatus.

摘要

A method of testing an electronic apparatus (1) which eliminates a control signal line for setting an integrated circuit (IC1, IC2, IC3) to a test mode and a test mode select terminal of an external terminal section and wherein fetching of test data and transfer of the thus fetched test data are performed in an integrated operation. In each of the integrated circuits, a boundary scan control circuit (8) discriminates a category code (Ci) at the beginning of data inputted from a serial input terminal (SI) to control a pair of switching circuits (SW1, SW2). When the category code represents a test mode, predetermined terminals (b) of the switching circuits (SW1, SW2) are selected so that input data are sent out to boundary scan cells (BC1 to BC8). Fetching of parallel data from parallel input terminals (PI1 to PI4) and transfer to the boundary scan cells (BC5 to BC8) are performed at one time.