ADF5902 TX switch between two consecutive chirp

Hi all

We are using ADF5902 in our 2T4R radar, The radar work in timde division MIMO mode ,it means 2TX channel of ADF5902 should be alternately on/off between two consecutive chirp.

In out desin ,we using Continuous Triangular Ramp, time of positive ramp  is 120us, time of negative ramp is 6us, and set  ramp done signal  to  muxout pin to trig adc sample .

if we don't  switch TX  between two chirp, everythings goes smoothly, radar work well.

if we write R0 register to switch TX  (during positive ramp or negative ramp), after write,  MUXOUT  don't  output ramp done signal, it seems  that ramp is stopped。

The question is

How to switch  tx on/off between  two consecutive chirps?

Thanks!