Structure and metrology for an analog testability bus

Using power supply current monitoring and P1149.4 for parametric testing of passive components

“…Fig. 3 illustrates the two configurations required to measure the value of resistor R. The method is similar to the one presented in [3] but now, instead of a current, a voltage stimulus is used and a current is measured. The resistance value is again computed by…”

“…To some extent, the design of the ABM was driven by the necessity to include features required for incircuit parametric testing of discrete componenrs [3]. Fig.1 shows the schematic of the proposed ABM structure, which is similar for input and output pins.…”

“…According to the method presented in [3] designated here as MA-the following steps have to be performed to measure the resistance R shown in fig. 1: -disconnect ICs cores by opening both CIl switches -close switches S, and S, in IC,, and S, in IC:…”

IEEE P1149.4-almost a standard

“…AT1 must support a current stimulus, and AT2 must support monitoring a voltage. [2] presents a proposed metrology to be used with this architecture. However, the Standard does not mandate the use of this metrology, as others could evolve with time.…”

“…In [ 3 ] , Whetsel re-presents concepts of [2] in a slightly different light. In particular, the concept of dividing control of the Analog Boundary Module into two sections, one for 1149.1 test resources, and one for P1149.4 was a major battle.…”