Análise de requisitos temporais para sistemas embarcados automotivos

Abstract

Automotive embedded systems are characterized by computer systems that support embedded software functionalities to provide users with greater comfort, security and performance. However, there are a number of integrated functions that raise the level of complexity so that appropriate design methods and tools must be used to guarantee the functional and non-functional requirements of the system. All automotive embedded software design must begin with the definition of functional requirements and according to the dynamics of the subsystem that an ECU (Electronic Control Unit) will control and/or manage, it is necessary to define the time requirements. An automotive function may have time requirements of type, activation period, end-to-end delay and deadline among others which in turn are strictly related to the characteristics of the hardware architecture used. In an automotive system there is a distributed embedded computing architecture in which there are tasks and messages that exchange signals between them and may have timing requirements that must be met. The timing analysis for verification and validation of timing constrains can be carried out at the level of distributed architecture, tasks and instructions, and the proper use of methods and tools is a necessary condition for their verification. In this way, a description of the state of the art of timing analysis in automotive embedded systems, their properties and the use of the tools of Gliwa to evaluate if the timing constrains are met. An illustrative example has been implemented with the purpose of presenting how the methods, processes and tools should be applied to verify that the time requirements defined at the beginning of the project are met and that in an existing system can support additional functions with requirements to be guaranteed. It is important to note that timing analysis tools are still intended to verify that computational resources are being used as specified at the beginning of the project.