LMX2571: FSK_I2S does not work with LMX2571

Part Number: LMX2571

we set LMX2571 as FSK_I2S_FS_POL_ACTIVE_HIGH and FSK_I2S_CLK_POL_Rising_Edge_strobe, FSK_EN = TRUE.

waveform of I2S is sent as follows, WS/CLK/DAT.But no frequency deviation