Abstraction level
Design (chronVAL, chronSIM), Implementation (chronEST, chronVAL, chronBUS, chronSIM), Operational (chronVIEW)
Use Cases
· Specify Timing Budgets
· Revise Erroneous Timing Information
· Specify Mode Dependent Timing Information
· Specify Probabilistic Timing Properties
· Integrate Reusable Component
· Specify System Dimensions
Covered aspect
WCRT (Functions, Tasks, ISRs), End-to-end delay (Event Chains), Jitter (Start, Terminate), Communication delay (SPI, CAN, FlexRay, LIN, Ethernet), Clock drift, Synchronization, Load (CPU, Bus), Sensitivity analysis, Multiple processing / Loss of data, RTOS errors, Scenarios and modes, Bursts, Probability distributions
Algorithm
Worst case response time analysis, Real-time calculus, System simulation, Residual bus simulation, Tracing and simulation
Inputs
· Hardware architecture (ECUs, Peripherals, IOs)
· Software architecture (Components, Signals, Functions)
· Communication architecture (Busses, Messages)
· Tasks, ISRs, Resources
· Execution times
· RTOS configuration / Scheduling strategy
· Stimulation (activation) scenarios
Particular constraints on inputs
Various standardized exchange formats such as UML, DOORS, DBC, FIBEX, ARXML, OIL, C code, CSV etc. can be used to import data from other sources.
The utilization of target specific C code in the simulation requires an associated specific hardware profile of the microcontroller.
Preparation of input
The INCHRON Tool-Suite is used to create a virtual prototype of the system under analysis that covers all timing relevant aspects of the software and hardware architecture as well as the system’s environment. For this purpose specific modeling views are provided, each focusing on a different timing relevant aspect.
Invocation of the algorithm
A virtual prototype model can be used to perform a WCRT analysis (clicking “Validate Model” in the GUI) or to start an interactively navigable simulation (clicking “Generate Simulation” in the GUI).
Outputs
WCRTs, event spectrum, trace of events
Visualization of results
· Response time composition
· Event spectrum viewer
· Sequence diagram
· State diagram
· Call-nesting diagram
· Event chain diagram
· Load diagram
· Histogram
· Requirements diagram
· Console
· HTML export
· CSV export
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