Abstraction level
Design
Use Case Tasks
· UC#0001 - Specify Time Budgets
· UC#0002 - Specify Mode Dependent Timing
Information
· Capture, Analyze, and Utilize Worst Case Timing Information
· Perform timing analysis on code level
Covered aspect
TimingExplorer estimates worst-case execution
times (WCETs) of tasks in real-time systems.
Here, a task means a sequentially executed piece of code (no threads, no parallelism, no waiting for external events,
and assuming no interference from the outside).
TimingExplorer solves the following subtasks of the evaluation of timing constraints:
A timing constraint refers to an event chain. TimingExplorer can compute the parts of the event chain that refer to
execution of the software on a processor. The other parts of the event chain like blocking times or message transfer
times are beyond the scope of the code level analysis by TimingExplorer.
Lately there has been an interest in performing a more
approximate WCET analysis earlier in the design phase, to support time budgeting and hardware dimensioning.
Therefore, TimingExplorer has been developed as a variant of the WCET analyzer aiT that is more flexible than
aiT on hardware configurations and more efficient for usage in earlier
development stages at the price of less precise results. Given linked binaries, it can perform a fast WCET analysis which allows a quick
exploration of different hardware configuration alternatives.
TimingExplorer requires the existence of binary code. On Design Level, it can only be
applied after generating and compiling some prototypical code, typically by employing a model-based code
generator.
Algorithm
Static WCET analysis optimized for speed to get analysis results for a variety of
hardware configurations quickly
Inputs
Hardware configuration, binary code, annotations on loop bounds, number of recursive
calls, targets of computed calls etc. that cannot be found by static analysis.
Particular constraints on inputs
Binary code for one of the following targets: PowerPC 5xx, 55xx, 56xx, 603e,
755s
Preparation of input
The hardware configuration can be specified by GUI options, textual descriptions, or
specification of the contents of configuration registers (details depend on the target architecture). Names of
executable and annotation files are entered in the GUI. From this information, a project file can be
formed.
Invocation of the algorithm
By starting the AbsInt a3 tool framework, loading a project file, and starting a WCET
analysis. The tool can also be started in batch mode without user interaction.
Alternatively, the a3 tool can be invoked from dSPACE’s TargetLink
tool.
Outputs
One WCET for each runnable, call graphs showing the structure of the analyzed code,
tables showing the distribution of the WCET to routines, textual report file, XML report file
Visualization of results
Graphs showing the structure of the analyzed program with analysis results attached
to the structure elements, tables showing the distribution of the WCET to routines
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