Optima Fault Injection Engine (FIE™) Technology
Optima’s safety solutions are based around a specialized fault analysis technology that makes use of a new fault injection engine verification technology.
As safety analysis for ISO 26262 and other safety standards fundamentally involves running simulations and injecting faults to examine their effect on design logic, fault simulation has been a natural choice as an analysis approach. Fault simulation is an inherently slow task, as the basic method involves running a simulation of an entire design without faults, and then injecting faults on specific signals one after another and rerunning the simulation for each to look for behavioral changes.
As such, the performance of the operation is proportional to a full simulation of the device multiplied by the number of signals in it, an enormous factor. Even though fault simulation is generally subject to a number of optimizations, such as fault pruning and collapsing, completion still requires weeks or sometimes months. Furthermore, traditional fault simulation is designed for manufacturing test where fault analysis is restricted to the asynchronous logic strung between flip-flops on a scan path, and machine-generated manufacturing tests. This scenario is different from safety verification, where the logic over multiple synchronous elements leading up to a safety mechanism, driven by operational test, sets must be examined. For this scenario, alternative methods are required to reduce analysis time.
Unlike other fault simulators used for safety fault analysis, Optima’s proprietary FIE algorithm set has been purposely built from the ground up to tackle the specific requirements of this operation. It makes use of a combination of modern verification techniques including advanced parallel simulation, formal verification, fault list optimization, and others to maximize the possible performance that may be achieved. In addition, fault-grading methods specific to the nature of safety fault analysis are applied to further reduce analysis time.
Acceleration of the analysis operation up to 1,000X over the next best alternative fault simulator has been observed consistently on real, commercial designs. An order of magnitude performance improvement is standard. The figure below shows a benchmark result on a large commercial processor design.
This high performance platform forms the basis of the Optima solution suite. By accelerating fault analysis time it is possible to complete unwieldy analysis in a fraction of previous schedules, as well as perform new analysis functions not previously possible.
In addition, the fault analysis algorithms allow for other operations to be performed, such as coverage maximization, which is essential to completing ISO 26262 safety analysis.