Efficient Scheduling

AutoFOCUS 3 supports an approach for supporting the system designer by generating schedules for an existing deployment. The generated schedules can be optimized towards timing.



Right-click on the project and open DSE (Design Space Exploration) where one can choose between Synthesis of Technical Architectures, Deployments and Schedules.



An Design Space Exploration (DSE) item opens in the Navigator View, containing already the manual deployment (from above). As we can use the DSE also for Scheduling Synthesis later on, the (Manual) Deployment is already there (if existing).

By double-click on the DSE in the Navigator a DSE Editor opens (see below). From this point on we can start doing either Technical Architecture Synthesis (left section), Deployment Synthesis (middle section), Schedule Synthesis (right section).



Scheduling Synthesis (right section)

Generation

Select the Deployments (there can be more than one, namely a manual deployment and previously generated ones) and hit Schedule Generation Wizard.

The next wizard page (below) allows to choose which components one wants to schedule. Either one schedules only the deployed components or all relevant atomic ones.



The next wizard page (below) allows to change the duration of signals.



This page (below) provides an overview over the component parameters such as WCET, Memory and SIL. Furthermore it provides a parameter overview for the ECUs.

Scheduling Synthesis using MSC Feasibility If you have specified Timing Requirements in a Use-Case description (cf. figure below) in the Requirements Analysis part, you could add these timing requirements as constraints. You can select all MSC Specifications that you want to add as constraints. After checking their feasibility, we would be able to integrate their timing constraints for the scheduling synthesis.

An overview is given of some Deployment-related attributes including enabling/disabling of timing parameter for the computation time of a component. You can choose either WCET -- that is the specified execution time -- or approx. WCET, which corresponds to an approximation based on the size of a state automaton inside a component.



DSE Scheduling Generation allows for enabling/disabling various Constraints and Solvers.
You can choose the solver to be used, depending on which one you have installed. For Yices SMT solver a max. end-to-end latency needs to be entered.
Furthermore you can find for a single valid solution or and optimzied solution w.r.t (for now) the optimization criteria of timing. Select a Timeout for the SMT Solver and hit Generate Deployments. When finished the "Next" button is enabled to go for the next Wizard page.



This next wizard page page (below) illustrates given results. Select all ("select all"-button) or select the ones you may be interested in. Hit "Save Selected Elements" and then "Finish".



All selected results are displayed in the Navigator View below the deployment for which the schedules have been generated. In our example the "Generated Deployment #2"



Double-click on a schedule would oben a new editor, where a "apply to system" button enables for adding the chosen schedule (incl. (generated) deployment to the system model.