Verification of Mixed-Signal Systems with Affine Arithmetic Assertions

Abstract

Embedded systems include an increasing share of analog/mixed-signal components that are tightly interwoven with functionality of digital HW/SW systems. A challenge for verification is that even small deviations in analog components can lead to significant changes in system properties. In this paper we propose the combination of range-based, semisymbolic simulation with assertion checking. We show that this approach combines advantages, but as well some limitations, of multirun simulations with formal techniques. The efficiency of the proposed method is demonstrated by several examples.

Simulation Based Verification with Range Based Signal Representations for Mixed-Signal Systems

“…In contrast to other range-based, e.g. [9,16], this implementation is capable of solving general nonlinear DAEs. This simulator has been verified to work with circuits consisting of at least 50 devices.…”

“…In [9] the behavior of linear analog circuits has been analyzed. Further, in [16] an affine simulation for mixed-signal systems has been proposed, however only transfer functions of electrical systems were simulated. Both [9,16] limit the use of affine arithmetic for analog circuit simulation drastically.…”

“…Further, in [16] an affine simulation for mixed-signal systems has been proposed, however only transfer functions of electrical systems were simulated. Both [9,16] limit the use of affine arithmetic for analog circuit simulation drastically. In [5,6] a different approach was used, which expands analog circuit simulation to take advantage of the symbolic information guaranteeing the safe inclusion of all results.…”

On more dependable assertion-based verification

“…In the previous work [8] the authors combine semisymbolic simulation with Affine Arithmetic Assertions (AAF+A). The AAF+A are introduced to allow automatic verification of simulation traces against desired specifications in contrast to the previous work [9] where simulation results are manually compared to desired system requirements.…”

“…Besides, assertion-based technology is also combined with formal methods like model checking as it is done in [12]. However in contrast to the work [8], the proposed methodologies do not not verify system robustness since the focus is only on nominal system behaviour. Any fluctuations in the manufacturing process or the environment in which the system operates are not taken into account.…”