No, becuase they are not listed in the Devnote. Why they didnt list them, I have no idea. There isnt even a hint of a serial port either. Just control lines they list. I guess it wasnt intended for 3rd party manufacturers to produce modems.
However If you pull the datasheet to the RCV144DPL, you will notice that the IC requires a Data and Address control bus. The IC does also give you a full RS232 serial port, but its Synchronous (USRT) so it requires a clock signal for the Send and Receive control lines, its for the V.24 compressor. But its all done in software/CPU i think on the duo. Plus, why would they have 50 pins on the connector? almost all of them are used it appears.
However If you pull the datasheet to the RCV144DPL, you will notice that the IC requires a Data and Address control bus. The IC does also give you a full RS232 serial port, but its Synchronous (USRT) so it requires a clock signal for the Send and Receive control lines, its for the V.24 compressor. But its all done in software/CPU i think on the duo. Plus, why would they have 50 pins on the connector? almost all of them are used it appears.