Hi,

Try looking for an application note at former Mitel site.

Not sure what's the new name of Mitel.

General search on the web will also take you somewhere.

Try downloading the data sheet of MT8840 from questlink.com that will have an application circuit.

You got to be careful on using this chip with 8051 ports. It is Motorola port compatible. To make it work with Intel ports, you got to say a magic spell ........

Simon