Test features of the MC145472 ISDN U-transceivers

The design of a single-chip implementation of a 2B1Q ISDN (integrated services digital network) U transceiver that meets the ANSI T1.601 standards has been completed. The MC145472 was designed with testability in mind and to be consistent with Motorola´s design-for-manufacturability goals. The authors describe in detail the design-for-testability techniques specifically intended for the IC manufacturer production test and other ad hoc test/diagnostic structures for the customer to use in evaluating system performance. A global test strategy for testing the ISDN U transceiver is presented. The test features have been used extensively not only for testing the device in the production environment but also for conducting evaluations and design verification experiments during the chip debugging phase. The test features described are well integrated with the architecture of the chip, thus minimizing incremental cost