C-based design flow: A case study on G.729A for Voice over internet protocol (VoIP)

In this paper we present the design of a G.729a codec in a C- based design flow. The codec is used in VoIP applications for sending speech over internet protocol. We started from the standard reference C implementation and generated several customized designs using the NISCT C-to-RTL toolset. Our final designs could run at very low clock frequencies (11 MHz for the decoder and 30 MHz for the coder) while meeting the timing requirements of the standard. We present these designs and the corresponding C-based design flow in this paper.