Abstract : The UML Profile for Modeling and Analysis of Real-Time and Embedded (RTE) systems has recently been adopted by the OMG. Its Time Model extends the informal and simplistic Simple Time package proposed by Uniﬁed Modeling Language (UML2) and offers a broad range of capabilities required to model RTE systems including discrete/dense and chronometric/logical time. The Marte speciﬁcation introduces a Time Structure inspired from several time models of the concurrency theory and proposes a new clock constraint speciﬁcation language (CCSL) to specify, within the context of the UML, logical and chronometric time constraints. A semantic model in CCSL is attached to a (UML) model to give its timed causality semantics. In that sense, CCSL is comparable to the Ptolemy environment, in which directors give the semantics to models according to predeﬁned models of computations and communication. This paper focuses on one historical model of computation of Ptolemy [SynchronousData Flow(SDF)] and shows how to build SDF graphs by combining UML and CCSL models.