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seamusbleu's avatar
seamusbleu
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3 years ago
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How to handle Stratix10 HPS-to-FPGA bridge ID width mismatch

The h2f_axi_master in the s10_hps has ID widths (AWID/ARID/RID/BID) of 4. I connect it to my custom IP which also has an ID width of 4 but platform designer complains that the ID width must be 5. I'm pretty sure that's because the h2f_axi_master is connected to the fpga_m2ocm_pb m0 bus.

So my question is, can I increase the ID width on the s10_hps h2f_axi_master bus? And if so, how? If not, how do I handle the mismatch?

This forum post suggests adding an AXI bridge. But that doesn't work as the AXI bridge requires the ID widths on both sides be the same.

I also tried editing the s10 h2f_axi_master ID widths in platform designer from 4->3. This seems to work, but when I create a build with this change, reads across the h2f_axi_master bus hang. I'm guessing it has something to do with the read/write/combined issuing capability is set to 16, but needs to be changed to 8.

Can someone tell me a good way around this issue?

16 Replies

  • seamusbleu's avatar
    seamusbleu
    Icon for New Contributor rankNew Contributor
    3 years ago

    Link to HPS-to-FPGA Bridge showing ID width is 4. This is also the case for the f2sdramN_data AXI slave buses. I need to connect them up to 3 of my custom IP which also have master ID widths of 4. In this case, I need the f2sdramN_data ID widths to go from 4->6 to accommodate the 3 masters. So the above question(s) applies here as well.

  • sstrell's avatar
    sstrell
    Icon for Super Contributor rankSuper Contributor
    3 years ago

    How do you have your addressing set up to each of the agents (slaves) the H2F bridge is connected to? It's not shown in your screenshot. And can you show the exact error/warning you are getting?

  • seamusbleu's avatar
    seamusbleu
    Icon for New Contributor rankNew Contributor
    3 years ago

    CTRL_axi_master has id width of 6, REG_axi4_slave and DMA_axi_master have id width of 4. There are 3 instances of the IP, thus the error message is that it wants me to add 2b to the s10_hps.f2sdram0_data slave axi bus that is connected to the CTRL_axi_master buses (same for the s10_hps.f2sdram1_data slave connected to the DMA_axi master buses). The s10_hps.h2f_axi_master is connected to the fpga_m2ocm_pb master, thus it wants me to add 1b to the REG_axi4_slave (or subtract 1 from the s10_hps.h2f_axi_master).

  • tehjingy_Altera's avatar
    tehjingy_Altera
    Icon for Regular Contributor rankRegular Contributor
    3 years ago

    Hi seamusbleu


    I am Jingyang and I am was assigned to this case.

    Please give me a moment to look into this issue and I will get back to you as soon as possible.


    Regards

    Jingyang, Teh


  • tehjingy_Altera's avatar
    tehjingy_Altera
    Icon for Regular Contributor rankRegular Contributor
    3 years ago

    Hi seamusbleu


    An update on this case, I am still working out internally with our team on the ID width mismatch issue.

    I am trying to check if is there a way to change the bridge ID width from Quartus.


    Regards

    Jingyang, Teh


  • tehjingy_Altera's avatar
    tehjingy_Altera
    Icon for Regular Contributor rankRegular Contributor
    3 years ago

    Hi seamusbleu


    Is it possible if you could share the quartus design file to us?


    Regards

    Jingyang, Teh


  • seamusbleu's avatar
    seamusbleu
    Icon for New Contributor rankNew Contributor
    3 years ago
    Do a "git clone https://github.com/altera-opensource/ghrd-socfpga.git ghrd-socfpga", then apply the changed files in the attached archive, then do a "make generate_from_tcl" and then "make quartus_edit", then open the qsys_top.qsys file and you will see the warnings shown above.
  • tehjingy_Altera's avatar
    tehjingy_Altera
    Icon for Regular Contributor rankRegular Contributor
    3 years ago

    Hi


    An update on this case.

    We are still working on this case internally.

    Sorry for the slow response.


    Regards

    Jingyang, Teh


  • tehjingy_Altera's avatar
    tehjingy_Altera
    Icon for Regular Contributor rankRegular Contributor
    3 years ago

    Hi seamusblue


    Sorry for the late reply.

    How are you reading the through the h2f axi bus?

    Could you share the method you are using to read the bus?


    Regards

    Jingyang, Teh


  • seamusbleu's avatar
    seamusbleu
    Icon for New Contributor rankNew Contributor
    3 years ago

    I'm not sure how or why that is relevant to the question about how to handle ID width mismatches, but we read through the H2F bus via u-boot, or linux - does that answer your question? I'd love to see an answer or some suggestions related to my question.