Agilex 5 GTS Reset Sequencer Intel FPGA IP : what value to set to i_refclk_bus_out with a PCIe IP ?

[Serge93]

Hello,

Using a PCIe IP in Root Port on a AGILEX 5, I have to use the GTS Reset Sequencer Intel FPGA IP configured in PCIe.

With Quartus 2025.1, the i_refclk_bus_out port appears on the GTS Reset Sequencer Intel FPGA IP.

There is no port on the PCIe IP to connect to port i_refclk_bus_out.

So, to which signal or to what value the port i_refclk_bus_out must be connected ?

Thanks.

Serge

[Wincent_Altera]

Hi ,

The i_refclk_bus_out is an input signal/reference clock who indicate the fail status signal from GTS PMA/FEC direct PHY FPGA IP or for other IP exclude PCIe IP.

If refer to https://www.intel.com/content/www/us/en/docs/programmable/813966/25-1/reset-signals.html

IF this is something that will causing the compilation to be fail, you may connect something call "refclk_bus_out" from non PCIe IP to the GTS Reset Sequence IP.

Regards,

Wincent

[Serge93]

Hello Wincent,

Thank you for your answer.

To be accurate, I can leave the port input i_refclk_bus_out floating without setting it to 0 or to 1, correct ?

Thanks.
Serge

[Wincent_Altera]

Hi Serge,

Theoretically Yes, as mentioned the clock is use for indicate the fail status signal from GTS PMA/FEC direct PHY FPGA IP or for other IP exclude PCIe IP.
If there is no anything to monitor , you can let it be floated, I never try this implementation before.
In cases the compilation is fail, please connected to any other IP who contain "refclk_bus_out/any similar" 

Regards,
Wincent_Altera

[Serge93]

Hello Wincent,

I do not have any other IP in my Platform Designer which contains any "refclk_bus_out/any similar".

So I wanted to know at which value should I set it, 0 or 1 ?

To make everything ok.

I did not find any information about that. 

Thank you.

Serge

[Wincent_Altera]

Hi Serge,

If you does not have the PHY IP inside your design, please set it as "0".
I try it in a simple design , I seeing the compilation passing, please have a try in rootport as well.
IF you seeing any new issue , please let me know the error code or any printscreen will do. We can solve this together.

Regards,
Wincent_Altera

[Wincent_Altera]

Hi Serge,

Are you able to try on yourside ?

Regards,

Wincent

[Wincent_Altera]

Hi,

Let me know if you need more time to response to this cases.

Regards

Wincent_Altera

[Serge93]

Hello Wincent,

Monday was off in France.

I could not answer to you because Quartus failed with the following error message :

Quartus 2025.1 fails when using the PCIe IP (GTS AXI Streaming IP) : 

    Error(24542): VHDL error at gts_axi_streaming.vhd(2001): expression has 20 elements; expected 22

I have a project test case to reproduce the problem.

Are you able to work on this problem ?

Thnaks.

Serge

[Wincent_Altera]

Hi Serge,

Is it possible to attach the design .qar file here ?
Let me check if I can help to resolve this or not.

Regards,

Wincent

[Wincent_Altera]

Hi @Serge93 ,

Below is my design for i_refclk_bus_out clock - ON the GTS Reset Sequencer Intel FPGA IP

the compilation pass as well

I attach the design .qar file here, please have a look.

Let me know if I could better assist you in anyway. Hope we can solved this.

Regards,
Wincent

[Serge93]

Hello Wincent,

Sorry I was busy yesterday.

Please pay attention the GTS PCIe IP must be configure in Root Port and not in End Point.

If you modify the GTS PCIe IP in Root Port in your project, I am pretty sure you will get the error.

Please find attached my test case.

Thanks for help.

Serge

[Wincent_Altera]

Hi Serge,

Please accept my apology for the mistake. I try to generate an Design example using RP.
But unfortunately it is not supported in current release of Quartus

Thanks for providing the design, Please allow me to have sometime to troubleshoot your design.

Regards,

Wincent

[Serge93]

Hello Wincent,

That is ok, do not worry, I did the same.

I did not try on a previoous version of Quartus, may be it can help.

Thank you.
Serge

[Wincent_Altera]

Hi @Serge93 ,

I try multiple combination of getting out from the error that you are seeing.
Including

1. adjusting the std_logic_vector (from 19 downto 0) -->(21 downto 0) -- As per mentioned with the error code
   But it keep coming with newest error where the other part of AXI logic is not compatible with it
2. This happen with other parameter and if else logic that I set as well.

With that, I believe those reset_sequence IP is not design for AXI Streaming root port originally.
If user insists to apply that, major modification on changing most of the element in different port in different file might needed.
those need to go one by one and it take sometime. And I could not guarantee by changing those parameter, it possible affected the pcie speed performance or not.

BUT....
We do have a Agilex 5 Root Port with completely prebuild .sof file with the exact same OPN number as yours current design.
Those design is freshly updated in last week.

Do you think that will be a good start for you instead of creating everything from scratch ?
IF YES, please try out https://github.com/altera-fpga/agilex5-ed-pcie-rp/releases/tag/25.1-1
All the file is included , you may refer to readme file for detail. Please let me know if you are facing any issue
I sincerely hope that can help you to move a step forward from your current obstacle

Regards,
Wincent_Altera

[Serge93]

Hello Wincent,

Thank you for your answer.

I had a look on the last release.

From my understanding, I have to remove everything except the GTS PCIe IP and the GTS Reset Sequencer and then add my logic ?

Meaning I have to use Platform Designer instead of files directly like I am doing, correct ?

I had a look on the code and I saw the 'i_refclk_bus_out' input from the 'gts_reset_sequencer' is connected to the PCIe reference clock, can you confirm that ?

This is the two main differences I saw compared to my design.

Thanks for help.

Serge

[Wincent_Altera]

Hi Serge,

Meaning I have to use Platform Designer instead of files directly like I am doing, correct ?
>> I believe there is a file locate somewhere else inside the design file.
>> You can either edit it via Platform Designer or VHDL code, but most of the design are written using SystemVerilog if I not mistake.

I had a look on the code and I saw the 'i_refclk_bus_out' input from the 'gts_reset_sequencer' is connected to the PCIe reference clock, can you confirm that ?
>> Yes, you may follow that, please try to run the compilation.

Regards,
Wincent_Altera

[Serge93]

Hello Wincent,

I tried to connect the  'i_refclk_bus_out' input from the 'gts_reset_sequencer'to the PCIe reference clock on my VHDL project but  I got the same error.

So next step is to generate a Plaform Designer project and see if I get the same error.

Please give me some time because I am busy on another project as well.

I will come back to you.

Thanks for help.
Serge

[Wincent_Altera]

Hi Serge,

Thanks for your update, is okay.. please take your time slowly.
Normally we would suggest user to use our design example if there is no other special needs.
Your design seen to be too simple, some logic might be missing causing the error.

So next step is to generate a Plaform Designer project and see if I get the same error.
>> you can delete other IP on the example design, I believe that will be more fast.

Regards,
Wincent

[Serge93]

Hello Wincent,

1) Yes I agree, but I do not see what in any documentation, even in the example design.

2) Not sure, I am afraid, do you have some time to do it for me ?

 I am busy on AGILEX 7-I-R-Tile project now.

Thank you in advance.

Serge

[Wincent_Altera]

Hi Serge,

1) Yes I agree, but I do not see what in any documentation, even in the example design.
>> What do you means what in any document, is there any specific things that you are looking at ?
>> IF have, please let me know I can help to find it if possible.
>> IF what you means is the step to run the design example under Altera GITHUB, you can get it via the .readme file
>> Other things else such as the IP user guide , you can get it via our FPGA documentation index https://www.intel.com/content/www/us/en/support/programmable/support-resources/fpga-documentation-index.html?q=sdi%20ii&s=Relevancy

2) Not sure, I am afraid, do you have some time to do it for me ? I am busy on AGILEX 7-I-R-Tile project now.
>> Sure, what you do with Agilex 7 R-tile ? 
>> Perhaps below documentation could help you to accelerate, feel free to refer that. (Those document are fully tested and publish by me)
>> https://community.intel.com/t5/FPGA-Intellectual-Property/How-to-run-PCIe-Gen-5-Design-Example-using-Altera-FPGA-device/td-p/1640988

Regards,
Wincent_Altera