4DSP Products Technical support

We would like to be able to acquire between 24 and 28  channels of data at 125 MSPS. We are considering installing FMC116 (HPC)  and FMC112 ((LPC) on the same kc705 board with firmware mainly based on 4DSP ref design to start. Is it feasible and does kc705 has enough resources for that?

Dear Sir,


This is possible; FMC116 can only be used on HPC and FMC112 can be used on both HPC and LPC.


The only issue I can see coming is the bandwidth.  In order to stream 28 channels at 125MSps, knowing a sample is 2 bytes wide, you would need a 7GB/s (Giga bytes per seconds) budget. I have to remind you that the ETHAPI layer is not a streaming interface and you wont be able to stream anything about 1-5 MB/s reliably.


On the PCI side, we have 2GB/s in the pocket and we are trying to reach 3GB/s which is far from your requirements anyway.


Best Regards,
Arnaud

Arnaud,


Thanks for prompt reply. We are indeed aware of bandwidth issues, the experiment is a burst waveform signal with low rep-rate cycle. To start, we plan to just expand a reference design, such as kc705_fmc116, add the other FMC star, expanding the router and command mux stars as necessary. The system would then acquire a burst of data, up to 64K per channel, the data will then be read in over Ethernet. Are there any obvious pitfalls? 

Dear Fedor,


It is a complex design, you should expect some slight issues here and there but no show stoppers. Getting all the channels synchronous over the two board is going to be the most difficult part I would say.


I hope that helps!


Best Regards,
Arnaud

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