regarding setting sampling frequency in fmcomms1 board

Hello Rahul,

For fmcomms1 you can set the sampling rate at 20,40MHz for Rx and Tx (this being the closest value to 20MHz) by setting in the main.c of no-Os driver the adcSamplingRate and dacSamplingRate in "defInit" structure at 20480000 or by calling in main:

XCOMM_SetDacSamplingRate(20480000);

XCOMM_SetAdcSamplingRate(20480000);

XCOMM_CalibrateAdcDco();

You can check if the wanted values where configured with:

ret = XCOMM_GetDacSamplingRate(XCOMM_ReadMode_FromHW);

xil_printf("%d \n\r", ret);

ret = XCOMM_GetAdcSamplingRate(XCOMM_ReadMode_FromHW);

xil_printf("%d \n\r", ret);

Is 20,40MHz a good sampling frequency for you?

Regards,

Andrei

hi Andrei,

              thanks your post has really been helpful but as you see i need exact 20 mhz sampling for transmission and reception , so could you tell me how to set that frequency , thanks

regards

rahul

Rahul,

Take a look here: how to adjust FMCOMMS1 ADC sampling rate at 40 MHz and multiples ?

If the oscillator (122.88 MHz) that drives the AD9523 is not good for you, you will have to replace the Crystek CVHD-950-122.88 VCXO part.

Regards,

Dragos

Rahul,

Unfortunately, without replacing the oscillator I don't think that you can obtain that frequency.

Regards,

Dragos

hi dragos,

                thanks for replying , is there any way i could use the existing oscillator to get a sampling frequency of 20 mhz by modifying some parameters if so can u help me with it, thanks

regards

rahul