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Visitor
Visitor
9,138 Views
Registered: ‎06-17-2015

JESD204 Transmission Problem

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I'm currently working on setting up a JES204 connection between a Xilinx ZC706 and a DAC FMC card. I have seem to run into a weird situation in my configuration process. I have programmed the JESD core on the FPGA side with the correct values, but my DAC is recieveing some incorrect values for the M, Subclass, and JESDV (jesd version) values. I have experimented some with the M value and found that I recieve the correct value on the DAC if the value is a 0,1,2, or 4. However if I try to use the value I need (a 3) the DAC recieves a 1C. The other problem is the 1s for subclass and JESDV turn into C's.

 

All the other values work fine, but for some reason these three don't appear to work properly. Would anyone be able to provide some insight?

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Xilinx Employee
Xilinx Employee
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Registered: ‎08-13-2013

Re: JESD204 Transmission Problem

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What is the DAC FMC card you are using? Check the serial P/N connections between the FMC and ZC706. You may need to assert TXPOLARITY to the transceiver if there is a mismatch. (It will still sync on K28.5 since the 10b codes are exact inverses).

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Teacher
Teacher
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Registered: ‎07-09-2009

Re: JESD204 Transmission Problem

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? signal integrity ?

 

is there a test mode in the system where you can test the link / BERT between two ?

 

wonder if the values change with tempature ?

 

just a thought ,

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Visitor
Visitor
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Registered: ‎06-17-2015

Re: JESD204 Transmission Problem

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I'm working on deciphering the frames the JESD204 IP block is sending to try and pinpoint where the problem lies. The interface syncs properly (the DAC tells me that it has recieved 4 consecutive K28.5 characters, the frames are synced, and it is getting ILAS), the checksum is not working properly.

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Visitor
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Registered: ‎06-17-2015

Re: JESD204 Transmission Problem

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Also the values seem to be consistent so it doesn't appear it changes with the temperature.
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Xilinx Employee
Xilinx Employee
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Registered: ‎08-13-2013

Re: JESD204 Transmission Problem

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What is the DAC FMC card you are using? Check the serial P/N connections between the FMC and ZC706. You may need to assert TXPOLARITY to the transceiver if there is a mismatch. (It will still sync on K28.5 since the 10b codes are exact inverses).

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Visitor
Visitor
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Registered: ‎06-17-2015

Re: JESD204 Transmission Problem

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I am using an AD 9154 FMC eval card. Where do I find the TXPOLARITY bit?

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Visitor
Visitor
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Registered: ‎06-17-2015

Re: JESD204 Transmission Problem

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Nevermind, I found that pin. However, if the polarity were incorrect wouldn't all of the values I am writing be wrong rather then only some of them? I'll give it a try nevertheless.
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Visitor
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Registered: ‎06-17-2015

Re: JESD204 Transmission Problem

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Well I'll be darned. That fixed it! Thank you very much for the help!

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