Abstract
A method for characterizing modulators is described which can be built in large integrated circuits or systems-on-chip. The method can be used to measure gain and phase, as well as, total harmonic distortion and signal to noise and harmonic distortion ratio parameters. It is prone to be built in circuit, when computational resources such as digital signal processors or re-programmable logic are available, but can also be used in computer simulations making it easier to compare expected with measured performances.

Abstract
This paper reviews special needs posed by today's technological advances in boards and MCMs, and addresses the requirements they place on Design for Testability techniques for assemblies of complex chips, both digital and mixed-signal. The IEEE P1149.4 mixed-signal test infrastructure is briefly described and its use as a means to support and implement different DfT techniques is described. Actual results are shown of its use on the implementation of a mixed current/voltage testing technique.

Abstract

Abstract
The use of cross-correlation between power supply current and output voltage dynamic responses is presented as a methodology for improved mixed current/voltage testing of analogue and mixed-signal circuits. Results obtained from simulations are presented which show that better fault coverage and a simplification of test circuitry can be obtained, when compared with the results obtained from the direct observation of the individual signals. These advantages are important factors to develop viable new design for testability and built-in self test techniques.

Abstract
The detection and location of faulty passive components is crucial in testing printed circuit boards. This issue is one of the objectives to be satisfied by the development of a mixed-signal test bus standard - IEEE P1149.4 - now on the final phase of evaluation. In this paper a method is presented that enables electronic in-circuit testing for presence and value of passive components, based on the use of analogue boundary modules like those developed under P1149.4, but making use of the positive power supply rail as an analogue test line. This method allows saving one analogue test line while profiting from the eventual presence of current sensors inserted for power supply current monitoring.

Abstract
The development of a mixed-signal test bus infrastructure - IEEE P1149.4 - is now in the final stages of the standardization process. Evaluating the test capabilities enabled by this infrastructure is an important step needed to support it as a well established standard. This paper presents experiments carried out with a test chip provided by the P1149.4 working group, which explore the architecture of the proposed analog boundary module to implement alternative testing methods. These include a method for parametric testing of passive components based on the monitoring of the power supply current, and a mixed current/voltage technique allowing the implementation of correlation for testing analog and mixed-signal macros.