Tool Mentor: Absint Timing Explorer (Implementation Level)
TimingExplorer estimates worst-case execution times (WCETs) of tasks in real-time systems.
Relationships
Main Description

Abstraction level

Implementation

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.

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