Combined control flow dominated and data flow dominated high-level synthesis

This paper presents the design of a Videophone Coder-Decoder Motion Estimator using two High-Level Synthesis tools. Indeed, the combination of a Control Flow Dominated part (complex communication protocol) with a Data Flow Dominated part (high throughput computations) makes this circuit difficult to be synthesized by a single HLS tool. The combination of two HLS tools for the high-level design of this operator required the definition of a sophisticated design flow allowing mixed-level and multi-language simulations. When compared to design starting from RTL specifications, HLS induces only a negligible area overhead of 5%, and provides gain in description length (divided by 5), design time and flexibility.