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The
appearance of sporadic errors in a late project phase, or even worse, after
start of production, are a testing nightmare. This is true for functional
errors, but it also applies to real-time errors - a frequent sort of root
causes behind sporadic issues. To detect, analyse and fix the entire spectrum
of real-time errors in a systematic manner, it is essential to create and
maintain a comprehensive set of real-time requirements, against which the
system can be verified. |
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| | For
this purpose, the INCHRON Tool-Suite supports 15 different requirement types. These
requirements types have been tailored to the needs of our customers. Measurement
results can be checked against the requirements based on trace logs (e.g.
iSYSTEM, Lauterbach, AURIX DAS tool interface), either post mortem, or
on-the-fly during test execution. In the latter case, sporadic errors can be
detected as soon as these occur.
The
intuitive, interactive and powerful visualization capabilities of the INCHRON
Tool-Suite facilitate the root cause analysis a lot. BTW, did you know that
understanding the root cause already contributes 80% to the total efforts to
fix the issue?
Within
functional safety, the net slack-time requirement is widely used to ensure and
confirm, that safety critical processes meet their deadlines. For autonomous
driving, the maximum end-to-end latency for functions and the data age are the
most important requirements. |
| | | This
example illustrates a scenario in which end-to-end latency requirement
violations happen due to small variations in a system that comprises several
activities sharing scarce resources. The first event chain (the series of
arrows connecting events from the top line to the bottom line, indicating
consecutive events that depend on each other) starts in the upper left corner
at t=0 ms, goes all across tasks running on CPU1, the CAN bus, and interrupts
and tasks running on CPU2. The event chain terminates within a so-called
end-to-end latency of 15 ms, which fulfils the real-time requirements in this
particular example. A second event chain of the same kind starts at t=20 ms.
Task T_10ms that starts at t=22 ms, however, takes longer to execute, such that
it is being pre-empted by T_05ms starting at t=25 ms. This even further delays
the execution of T_20ms on CPU1. Moreover, T_20ms takes more time to execute as
well, such that it runs into further preemptions. As a consequence, this event
chain terminates at the interrupt I_CanRx on CPU2, far too late to be taken
into account by the periodic task T_20ms starting at t=31 ms on CPU2. Depending
on the way the software is implemented, this issue may either result in data
loss, or unintended data reuse. |
| | Further
information about requirements and many other topics can be found in our
Tool-Suite manual. Now available online! |
| | Are
you interested in our comprehensive requirement list? |
| | | Get
more information about our intuitive, interactive and powerful visualization! |
| | | Meet us at
Learn more
Contact us Questions? Callback? Request a quote? Reply to this E-Mail or call +49-331-279-7892-0 |
| | | INCHRON GmbH, Karl-Liebknecht-Str. 138, 14482 Potsdam; Executive
Management: Dr. Ralf Münzenberger, Matthias Dörfel; Registered at Local
Court of Potsdam (Germany) under file HRB 23358P. Please see our Privacy Policy. |
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