Enhancing the boundary scan standard to test resistively-terminated printed circuit board interconnects

The performance of many digital systems requires that the interconnections on a printed board assembly (PEA) are considered as a transmission line. The authors present details of a method of using the boundary scan test technique to test for the presence or absence of the terminating resistors required, in addition to a conventional interconnect test, during manufacturing. Details of the test sequences and general purpose detector circuits which have been designed and fabricated in CMOS technology are presented.