How to using OCM on zedboard?

[hengzhao]

Hi,

Could any one tell me how to write OCM from PS and read from PL?

I used to write DDR from PS and read from PL. But accessing ddr could be slow. Since my data is not that big. I want to use OCM to accelerate the process.

The screenshot below is how to used to access the data using DDR. Now, in order to using OCM, I just mapped the address from DDR to ocm(0x0000_0000 to 0x0003_FFFF). From the ps side, I write the data array to the address start from 0x0000_0000, and from PL side, I changed the read address to 0x0000_0000. I could still get the correct result, but the run-time is still almost the same. Any idea why it is not working?

[jpeyron]

Hi @hengzhao,

I do not have much experience with this type of project. I did find some information here and a xilinx forum thread here that might be helpful.

thank you,

Jon

[hengzhao]

Hi @jpeyron

Thanks a lot for your reply.

That is how to set my project. And a little update on the result, the run-time changing from 0.21s to 0.197. It has about 1.1X speedup. Is this normal? (Because I expect much more faster)

Thanks,

Heng

 

[jpeyron]

Hi @hengzhao,

I do not have much experience with this type of project. I do not know if the 1.1X speedup is  normal. I would suggest to reach out to xilinx support about this.

thank you,

Jon