Designing a flexible compilation framework for cal language

The CAL, created as a part of the Ptolemy II project, is an open source actor-based data-flow language. Some of its contributors are Xilinx, Ericsson research, and the MPEG-consortium. More information about CAL can be found at opendf.org. Today there exist several back ends for CAL, all share a common front end, which translates the CAL language to an intermediate format called XLIM. The back end then translates XLIM to the target language, i.e., VHDL, C, and ARM (C code and run-time environment). The existing tool chains are based on XML and XML transformations (XSLT), but the expressiveness of the XSLT language limits which transformations can be carried out. Furthermore, some parts of the existing front end are note.