Using haloes in mixed-signal assertion based verification

We develop an assertion based verification solution for analog mixed-signal designs. We introduce the halo concept for analog signals to express them with their tolerance and variation values in assertions. The halo of a signal provides a relaxation over the signal and it defines an effective region for that signal which can be used in assertion based verification. Using haloes for analog signals allow us to define a new set of comparison relations between two analog signals including their equivalence. In our intended design flow, these new analog signal operators are placed into the Analog layer of mixed-signal assertion languages as an extension. We present experimental results on a programmable switch and a VCO.