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FMC204 SPI reference design for ML605

Dear 4DSP Support


I'm trying to use FMC204 with ML605 to transmit data continuously.

I have FMC204 reference design with ethernet communication.

Is there any other FMC204 reference design with SPI communication?



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Dear Sir,

This is something customers/integrator need to do themselves, this is about modifying a design so it can be used in your design.

4DSP can do that for you but you should then contact and arrange that with them. You should expect NRE costs if we do this potion of your job for you.

The pointers I provided are valid and should be enough for your design.

Best Regards
Dear Arnaud,
Thank you for your reply.

I realize that the bandwidth on the Ethernet link is very low. However I could potentially replace the Ethernet MAC with the PCIe MAC and get much higher bandwidth.
If a PCI star for the ML605 is provided, I could use that or I might be able to create one myself ?

When you [font=Verdana][size=small]say[/size][/font][/size][size=78%][font=Verdana] "[/font][/size][size=small][font=verdana][/size][size=11px]FMC204 shall be modified to not have a waveform memory and push data received from the data bus directly to the DAC"[/size][/font][font=Verdana][/size][size=10px],[/size][/font][font=Verdana][/size][size=2] is there one being developed ? If yes, when is the release expected and can I get access to that ?[/size][size=10px][/font]

[font=Verdana][/size][size=2]Thank you,[/size][size=10px][/font]
Dear Sir,

These features could be implemented but are not available in the reference firmware. You are indeed correct, the application uploads data to a waveform memory and the samples are then played back.

FMC204 shall be modified to not have a waveform memory and push data received from the data bus directly to the DAC. Investigation on the data bus bandwidth is required to know if you have enough bandwidth or not.

The steps to reach these goals are unfortunately not covered by technical support so this will need to be implemented by you.

On the software side, the API is offloading data so in theory you could stream data. The problem is more about the bandwidth available on the Ethernet link, only a couple of MB/s which is not going to be enough to stream the DAC device.

Best Regards,
Hi Chris/Arnaud,
Could you figure out how to stream data to 204 ?

It seems to me that the fmc204APP send a block of data to the ML605 that stores it in onboard memory (WFM) as specified by the FMC204 star.  I think the FMC204 star then (when 'arm'ed) continuously sends this buffered data to the DAC5682 and loops around when it reaches the end of buffer.

I am trying to figure out if there is a way to :-
1. Instruct the FMC204 star to STOP ('disarm') at end of buffer.
2. Poll FMC204 star to figure out if it has reached the end of buffer.
3. Then send a new block of data to the buffer and arm it again.

This I think will help stream data to 204 outputs. The only drawback I foresee is transmission delays between successive blocks of data. This could be resolved if there exists a shadow buffer that can be written to while the FMC204 star is busy sending the buffered data to the DAC5682.

Is such a functionality available through the 4DSP API ?


Hello Chris,

The reference software communicate to the ML605 over Ethernet and the firmware communicate with the chips using SPI.

This is the only reference design we have available.

Best Regards,