# Relation between CGEN, ADC, RxTSP, DAC and TxTSP clock frequencies

Hello @Zack ,
Kindly correct my understanding:
Understanding: If 0x0086 [EN_ADCCLKH_CGEN] is default, FCLKH = CGEN and FCLKL = FCLKH (unlessCLKH_OV_CLKL is set to something other than divide by 1).
DAC and TxTSP operate at FCLKH and ADC and RxTSP operate at FCLKL.
Based on this TxTSG when set to NCO default, should generate a tone at CGEN/8.
Eg: When CGEN is set 200MHz, a tone is expected at 25MHz.

Issue: I am seeing a tone at half the frequency i.e.,
CGEN Expected Tone Observed Tone
50MHz 6.25MHz 3.125MHz
100MHz 12.5MHz 6.25MHz
200MHz 25MHz 12.5MHz

Is the actual frequency being divide by 2 again?
Regards,

Hi @EnthuMan,

From this post:

Tone frequency will be Ftxtsp / 8 (or 4) / DecimatioRatio. If TSGFCW[1:0] = 01b, TSGMODE = 0, INSEL = 1, HBD_OVR[2:0] = 000b (i.e. decimation by 2), then tone frequency generated by RxTSG will be 50/8/2 = 3.125MHz. Sample rate of this tone will be 25MHz, not 50 (decimation by 2, remember?).

Thanks @Zack.
And apologies for missing your input from an earlier post.