RTOS/CC2650: Can I change the sample rate of the PDM driver?

Part Number:CC2650

Tool/software:TI-RTOS

I want to sample the audio of frequencies up to 20khz, but the default PDM driver sample rate if only 16khz, so can I change the PDM driver sample rate?( It seems there is nowhere in the driver file I can change the sample rate)

Thank you in advance