Here is a document I found, Its a Zilog application note and explains how to implement localtalk using their SCC, Including the source code

http://www.zilog.com/appnotes_download.php?FromPage=DirectLink&dn=AN0064&ft=Application%20Note&f=YUhSMGNEb3ZMM2QzZHk1NmFXeHZaeTVqYjIwdlpHOWpjeTk2TVRnd0wyRndjRzV2ZEdWekwyeHZZM1JoYkdzdWNHUm0=