Profiling of SIGNAL programs and its application in the timing evaluation of design implementations

We present a tool currently under construction in order to enhance the SIGNAL language environment with a facility that will allow the temporal validation of a system specification with respect to its R/T constraints while staying within the context of the SIGNAL language. By use of the so called temporal homomorphisms we express the temporal dimension of a functional specification as a SIGNAL program. This facility can be further extended to evaluate the temporal behavior of a system with respect to a chosen execution architecture, by modelling processor architectural features influencing execution time. Reasoning about the timing properties of a program is indispensable in the development of time critical systems where failure to meet deadlines can result in loss of life or material. There is much work done in the domain of functional specification where formal languages like SIGNAL, Esterel, Lustre can be successfully used. There seems to be an inadequacy as far as the validation of temporal properties is concerned and this is mainly due to the fact that many different factors influence the execution time of a program making this problem quite complicated when viewed from a high abstraction level.