SWITCHING BOUNDARY SCAN TEST DEVICE

摘要

PURPOSE: A switching boundary scan testing apparatus is provided to determine in which apparatus an error has occurred if the error occurred in one apparatus, and perform a reliable test for other apparatuses. CONSTITUTION: A switching boundary scan testing apparatus(300) comprises a first boundary scan cell(310), a first input multiplexer(320), a second boundary scan cell(330), an output multiplexer(350), a joint test access group circuit port(340), and a switching unit(360). The first boundary scan cell receives an input of a test signal from the joint test access group circuit port and outputs a first output test signal testing a first device into the output multiplexer or the first input multiplexer. The second boundary scan cell receives an input of the test signal from the first input multiplexer or outputs a second output test signal testing a second device into the output multiplexer. The output multiplexer is connected with a test data out terminal(TDO) among the joint test access group circuit port and selectively outputs a test data output signal. An output signal of the output multiplexer is determined by the switching unit. [Reference numerals] (310) First boundary scan cell; (320) First input multiplexer; (330) Second boundary scan cell; (340) JTAG port; (350) Output multiplexer; (360) Switching unit