AFE7950EVM: configure LMK04828 in AFE7950EVM

thanks for answer David,

yes I want to modify the sampling rates to something maybe is not feasible with the internal reference of 122,88MHz used to feed all the clocks in the EVM and JESD interface.

I want to use a sampling rate in the FPGA about 64Msps.

just discover there is another example who use an external reference (TI_IP_5Gbps_2lanes_4Rx_ConfigLmk.py)  and would like to see if this can solve our requirements.

the parameters used for this example:

lmkParams.pllEn = False

lmkParams.inputClk = 983.04 # Valid only when lmkParams.pllEn = False

lmkParams.lmkFrefClk = True

setupParams.fpgaRefClk = 61.44

this example use a sampling rate of 2949.12MSPS and a ddcFactorRx of 48 so my sampling rate in the FPGA is 61,44MSPS.

what should I configure in this example to achieve the 64Msps?.

I have tried to feed the EVM with external reference of 1024MHz and the example seems working correctly but if I configure the parameters in the scripts according the real values gives me errors of not compatible values of internal VCO frequencies in range so not sure if I'm doing it correctly.

Also after that I need to enable the tx channel with twice the sampling rate and a ducfactor of 48 to achieve a sampling rate of the FPGA of 128MSPS but I see the configuration of this example is not correct. so I guess i have to change more parameters to achieve this.

the example have the next parameters for the transmitter:

sysParams.Fdac = 2949.12*3

sysParams.txEnable = [False,False,False,False]

sysParams.ducFactorTx = [18]*4 #DUC interpolation factor for TX A, B, C and D

sysParams.jesdTxProtocol= [0,0]

sysParams.jesdTxLaneMux = [5,1,2,3,0,4,6,7]

sysParams.LMFSHdTx = ["44210","44210","44210","44210"]

as far I can understand these parameters seems not suitable for 2 lanes and 5gbps, at least tried to only enable the TX part in the script and FPGA and is not working (with errors in the JESD link).

the only changes I made in the FPGA project is change the parameter IP_TYPE to "RXTX". the others parameters were configured as:

NUMBER_OF_RX_LANES 2
NUMBER_OF_TX_LANES 2

LANE_ADC_TO_GT_MAP {0,1}

LANE_DAC_TO_GT_MAP {0,1}

RX_LANE_POLARITY 2'b11

TX_LANE_POLARITY 2'b11

Some guidelines or maybe the correct parameters for my goal would be much appreciated.

Thanks

Hi Juli,

If you can fill out the table below i can create a custom script for you.

Regards,

David Chaparro