Using a function generator rather than a TCXO with the CC1120

Hi,

I was wondering if it was possible to use a function generator to input a sine or square wave through a series capacitor into the CC1120 EXT_XOSC pin rather than a TCXO? I know the datasheet says the TCXO uses a clipped sine wave, does this mean a function generator cannot be used?

Many thanks

Elliot