Feature: Embedded
Figure 1: Horizontal and vertical usage for C-based tests
management tool (Figure 2), designed to control regression suites and only run scenarios if previous, related checks have run and passed first. The tool generates detailed reports and ensures high-quality verification with less manual work. For designers, not only must they do
Random behaviour Meeting functional safety standards for electronics, such as ISO26262 for automobiles, is a key part of verification. In ISO26262, there are two types of faults: systemic and random failures. The systemic failures are those historically looked for, relating to bugs found during development and manufacturing. Random failures can come from the degradation of parts, as well as environmental effects, which can cause a design to misbehave. Radiation from cosmic rays or solar flares is a typical example of an environmental effect that can cause errors in a design. Known as latch-up, it is a type of short circuit that could have serious consequences in mission- or safety- critical applications. As chips become larger, the greater the chance of a latch- up. Smaller process geometries also increase the possibility of latch-up. Although random faults have always
happened, a consumer usually lives with them, seeing them as a minor device misbehaviour. A mobile phone not responding is typically remedied by switching it off and on again. However, in a safety-critical application, this is not possible – there’s no scope for things not working properly or the user finding a patch-up fix. Traditional techniques are aimed at finding systemic faults but not faults that might exist in the design. Tools that find random faults should
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be integrated into design flows. The random effect can never be removed, so the design’s architecture must incorporate ways of detecting a fault when it occurs.
Regression management tool An interesting technique we have developed at Sondrel is a regression
everything properly, but also must prove it with detailed auditing and tracking, an increasingly important aspect in standards compliance and when handling larger designs. A small change or error can have a significant effect later on, so with detailed records, problems can easily be identified and corrected. Gone are the days when one person
could hold an entire design in their mind: verification, auditing and tracking enables it to be spread safely between the many minds now needed.
Figure 2: Regression manager tool
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