A Mixed-Signal Test Bus and Analog BIST with ´Unlimited´ Time and Voltage Resolution

This paper describes a test bus suitable for conveying analog and digital signals to/from an unlimited number of circuit nodes with almost unlimited time or voltage resolution, in contrast to analog buses which are unlimited only in voltage resolution. A strategy is described that extends a silicon-proven approach for BIST of jitter and delays in PLLs, to BIST of ´random´ analog functions. A variety of stimulus and response capture approaches is used to translate analog parameters from any number of circuit nodes, addressed by a P1687-like scheme, into digital waveforms conveyed via digitally under sampled serial bit streams or analog over sampled sigma-delta bit streams, to shared RTL-synthesized measurement circuits. Examples are presented for diverse circuit parameters.