Discrepancy between time calculated by vitis hls report and that calculated on PYNQ

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1

hello everyone,
I have an IP created on vitis HLS 2023.3, through the synthesis I calculated the expected processing time. With Vivado I integrated my IP in order to exchange data via DMA with the ultra96v2. If I calculate the time between reading the data and writing the result (both with DMA) on PYNQ, through the Python time module, I find a much lower processing time. how is it possible?
Thank you

2

Hi @T_A,

If you are measuring the execution time from the PS using the Python module time, you are measuring the communication time with the PL and some uncertainty introduced by the OS. Also, the resolution of this module is much lower that what you can measure in the PL.
If you want to measure the execution time of an IP, the best way would be to add PL timers.

Mario

3

Hello
Thank you for your answer.
I understand what you mean, in fact I expected to measure a much longer time with PYNQ than measured through the Vitis HLS report.
Can you tell me why?
Thank you

4

What measurements did you get in the different parts?