I am looking at the documentation http://www.ti.com/lit/ds/symlink/cc1121.pdf
7.1.1.1 Configuration Software The CC1121 device can be configured using the SmartRF Studio software (SWRC046). The SmartRF Studio software is highly recommended for obtaining optimum register settings, and for evaluating performance and functionality.
Ive downloaded the link and installed
I now have SmartRF Studio with an number of tabs however none refer to the CC1121