AWR1642: parameter from labs0002 can not be config in mmwave stuido

                                                                                                                            fig 1

I am using AWR1642+RTSW1400 to capture adc date. and using postproc in mmwave studio check the adc data.

I extract config parameter from \mmwave_automotive_toolbox_2_0_0\labs\lab0002_short_range_radar\srr_target\common\srr_config_chirp_design_SRR80.

When i config chirps 0~63, mmwave studio tells me Ramp End time is too short for 256  samples at 5MHz.

I do not know why. Why lab0002 can config this parameter, but mmwave studio can not?