SpecCharts: a VHDL front-end for embedded systems

VHDL and other hardware description languages have become popular as system speci cation languages in top-down design. However, their constructs do not support the behavioral speci cation of embedded systems. We introduce a new conceptual design model, called Program-State Machines, that caters to embedded systems. We then describe the SpecCharts language, an extended version of VHDL, which supports capture of this design model. In conjunction with a translator to VHDL, SpecCharts can be easily incorporated into a VHDL design environment, with the advantages of signi cantly reduced speci cation time and fewer errors. The extensions introduced for VHDL are applicable to many other hardware description languages as well. We demonstrate the advantages of using SpecCharts for system speci cation capture through several experiments.