How do I load a file of numbers into registers on FPGA

[jialunluo]

Hi all,

I am trying to build an FIR filter and one step I need to do is to load an array of numbers (these numbers are predetermined so they are fixed during the runtime) into some registers on the FPGA. How can I do this?

Thanks in advance,
Jialun

[Nils Roos]

Hi Jialun,

if you are implementing your filter as an extension of the existing Red Pitaya logic, you should mimic the mechanisms that are used to program parameters, eg. in the scope module. The design provides a simple internal bus where you can attach registers and access them from the application side.

If your design is not based on the existing infrastructure, you could take a look at the "FIR Compiler" IP. You can configure it to have programmable coefficients, which can be made accessible through an AXI interface. You can then connect the configuration port to a free AXI master on the PS and program it that way. Refer to the IP docs for more details.

If the "FIR Compiler" does not meet your requirements and you'd prefer to implement the filter yourself, you could take a look at Pavel's axi_cfg_register. It is an arbitrary width register with a memory mapped AXI interface. Connect it to a free AXI master port on the PS.

[jialunluo]

Hmmm, I think it will be easier for me to base the filter on the existing red pitaya infrastructure. By mimicking the scope module, are you referring to the lines of system write and read based on the register addresses? (I couldn't refer to specific lines on github as I was unable to find the file... But I think I saw it once. Could you refer me to the file and the lines if I am wrong on this?)

On the other hand, (perhaps not so relevant to this post), I am quite interested in learning to use Zynq from a more basic level. However I don't have a background in embedded system developing. (I have only tried a spartan-6 on a digilent board before and modified some red pitaya FPGA code). Do you have any recommendations of resources?