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MAlek2's avatar
MAlek2
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6 years ago

Division in HLS doesn't work

I'm trying to write a simple matrix inversion program and the generate an HDL code from it. I'm working with fixed point math. Here is a part of my code: typedef ac_fixed<40, 20, true> fixed_40_2...
KhaiChein_Y_Intel's avatar
KhaiChein_Y_Intel
Icon for Regular Contributor rankRegular Contributor
6 years ago

Hi,

I notice that you modified the message from gives the answer c = 3.572222 which is wrong to gives the answer c = 3.572222 which is right. Do you see the expected behavior?

We have one example for fixed point in <quartus_installation_directory>hls\examples\tutorials\ac_datatypes

Thanks.

  • MAlek2's avatar
    MAlek2
    Icon for New Contributor rankNew Contributor
    6 years ago

    Yes, with that code it was my mistake. But with the matrix calculations it was not. Anyway i played with that code and found out that placing string

    denomerator = matrix_A_src[i][i];

    inside of the loop was a bad idea. So when i moved that string outside of the loop i got my code work.

    But than i stuck with another problem. I'm trying to compile generated code for Cyclone 10 GX and Quartus 17.1 completely stucks at analysis step. The error message says it is not enough memory for compiling this code. But as you can see the source code is very simple. I played with #pragma unroll and sometimes HDL code just can't be synthesized because it is too big for Cyclone 10 GX.

    So my next question is how can i find out why does my code is synthesized in some wrong way leading to a very large area?