Alternative test methods using IEEE 1149.4

IEEE 1149.4 infrastructure has been aimed primarily for printed circuit board (PCB) interconnect test, parametric test of discrete components and functional test of IC cores. Methods to perform these tests have been published and experimental results using evaluation samples of IEEE 1149.4 ICs have been reported. So far, most attention has been paid to test and measurement techniques for the first two issues. Proposed methods typically employ IEEE 1149.4 infrastructure in the function of a built-in test probe that enables external test and measurement equipment to access the internal PCB points via the analog test bus. This paper describes an alternative approach based on functional transformation of the tested board by means of the existing IEEE 1149.4 resources. In this way, efficient go no-go functional test can be performed. Case studies are given to illustrate the proposed approach.