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Original question:

AFE7954: Latte(AFE79xx) spi_convert.py directory

AFE7950: AFE7950 EVM [PCB REV A DC135] : AFE79XX Lattice GUI Configuration Issue.

Guruthathathreya S
Prodigy 30 points
Part Number: AFE7950

Tool/software:

Hi,

 I am trying to configure the AFE7950 EVM board with AFE79XX Lattice GUI. 

For FadcRx, Fref and Fdac, if I am giving the values as shown below  and run the buffer I am not getting any error :

sysParams.fbEnable                        = [False]*2
sysParams.externalClockTx            = False
sysParams.externalClockRx            = False
sysParams.FRef                               = 491.52
sysParams.FadcRx                           = 2949.12
sysParams.FadcFb                           = 2949.12
sysParams.Fdac                               = 2949.12*4

decimation = 6

interpolation = 24

With the above configuration its running fine.

But, I need Fadc as 1.966.08Mhz. So I have made the changes as shown below:

sysParams.FRef = 491.52

sysParams.FadcRx = 1966.08

sysParams.FadcFb = 1966.08

sysParams.Fdac = 1966.08*4

sysParams.externalClockRx=False

sysParams.externalClockTx=False

decimation = 4

interpolation = 16

Also I have changed the Top System Parameters in the AFE79xx_SystemParameters excel sheet at the location: C:\Users\..\Texas Instruments\AFE79xxLatte\lib\Afe79xxLibraries\AFE79xxLibraryPG1p0\resourceFiles.

But there I am getting error as shown in the below snapshot.

 Could you please provide the details of what all configuration parameters and files that we need to change if we are changing fadc and fdac ?

  • 0
    Prodigy 30 points

    Kindly request you to reply this issue ??

  • 0 in reply to Guruthathathreya S
    TI__Genius 17891 points

    Hi,

    You are changing the samples rates correctly. The only issue you are having is that the samples rates chosen do not fall into the supported range of the internal VCOs, as indicated by the red errors in the Latte log. For this specific sample rate you would need to change to using an external clock, for this i would recommend following the steps outlined in the "AFE79xx_EVM_External_Clocking_Guide.pptx" document. 

    If you would like to not use an external clock then you would need to adjust the sample rate such that it falls within the supported ranges.

    Regards,

    David Chaparro