AD9988 CDDC and FDDC

Question

Hallo, 
 I wonder if the CDDC and FDDC of AD9988 should be set the same to CDUC and FDUC? 
 
 First, I set CDDC and FDDC = 2x3，CDUC and FDUC = 2x3，JTX and JRX link can both be established. 
 Second, CDDC and FDDC = 3x2，CDUC and FDUC = 2x3，JRX link can be established, JTX can't. 
 Third, CDDC and FDDC = 6x1，CDUC and FDUC = 6x1，JTX and JRX link can both be established. 
 
 My configuration parameters are as follows: 
 ADC clk= DAC clk =3686.4MHz，ADC JESD204C：L=8, M=8, F=2, S=1, K=128, E=1, N=16, NP=16 
 
 Is there any limit that CDDC and FDDC of AD9988 should be set the same to CDUC and FDUC?

UmeshJ · Accepted Answer

pgy123 said: I wonder if the CDDC and FDDC of AD9988 should be set the same to CDUC and FDUC? 
 not necessarily. you need to make sure that the serdes line rates on the DAC (Tx) and ADC (Rx) sides are matched. 
 pgy123 said: Second, CDDC and FDDC = 3x2，CDUC and FDUC = 2x3，JRX link can be established, JTX can't. 
 This might be because the combination of CDUCxFDUC is not supported 
 pgy123 said: Is there any limit that CDDC and FDDC of AD9988 should be set the same to CDUC and FDUC? 
 you can use https://www.analog.com/en/license/licensing-agreement/jesd204-mode-selector-tool.html to understand the supported modes.

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AD9988 CDDC and FDDC

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