PA1688 Solution     This VoIP solution was designed by us when we were with Centrality from 1999 to 2005. The chip has an 8-bit 8051 core to handle VoIP related protocols and a 16-bit DSP to process voice. What is new: software 1.68 updated on Jan 21, 2012. PA1688 was discontinued by Centrality in early 2006. We are still fixing software bugs, but no longer adding new features any more.   Software support, hardware design, reference settings, ring tones download, FAQ, miscellaneous.