New Contributor
New ContributorHi,
In terms of additional resources to help check if your coefficient update method is correct, have you looked at the coefficient software drivers that are supplied in some of the design examples? This one for instance: https://www.intel.com/content/www/us/en/design-example/714758/intel-arria-10-fpga-intel-8k-displayport-video-format-conversion-design-example.html
The software uses C++ drivers for each VIP core. The source code for each driver will be included in the Nios II BSP for the design (run the compile to generate it), and the scaler's source code includes functions to generate a load coefficients. You say that you are using a verilog state machine to do this, so the software is not something you can just use directly, but it should be a good additional guide as to which registers need to be written and with what values to successfully load new coefficients.
If this is no help and you are still having problems then perhaps you could upload a screenshot of the scaler parameter set, and maybe some signaltap screengrabs that show the update in progress?
Thanks
New ContributorThanks very much for the hints, and for jumping in, it is VERY much appreciated.
Based on continuing experimentation here (and on various hints, too), I think I have determined that we were writing coefficients properly/effectively, but the coefficients were in fact scrambled; in particular, it seems that we were writing the taps in inverse order from what the IP was expecting -- based on trying to follow the apparent ordering in the Megawizard-generated .mifs which resulted from using default coefficients at compile time. I swapped that ordering, and am now getting desired/expected results. I still plan to refer to the way they are being written in the design example you pointed me to (haven't taken the steps in that path yet, but want to cement my understanding better).
I had also started an IPS ticket (at the suggestion of our distributor rep), also being concerned about some of the apparent strangeness in the VIP User Guide; I still/now think that there may be issues there (which had also caused me to doubt if we were writing things correctly), but I will perhaps take those up further in that venue.
So I think I might be off and running now -- assuming I don't run into something else (in which case, I may have to return here, but after I bang my head again for a while)...
Many thanks again!
New ContributorAha -- I see that you've also been in contact with the IPS side...
