The CMX7261 acts as an audio codec capable of encoding analogue voice into linear µ-law or A-law PCM, CVSD or G.729A data formats. It is capable of decoding PCM, CVSD and G.729A back to analogue voice. It can also transcode data between PCM, CVSD and G.729A.
This video gives an introduction to the CMX7261, its features, and suitable applications.
https://www.youtube.com/watch?v=xFaU7pfkcWI