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Cyclone V PCIe HIP is stuck at L0 state and no activity on tl_cfg_ctl & tl_cfg_add


Design Description:

•PCIe – I2C design.

•PCIe x1 Gen 1 with application side running at 62.5 MHz

•Porting the design from Xilinx Artix 7 device to Intel Cyclone V.

•Application side is programmable IO state machine that drives the I2C interface.


Failure Symptoms:

•LTSSM state – L0

•No activity in signal Tap on tl_cfg_ctl & tl_cfg_add

•PCIe config space shows Correctable errors and Unsupported request in the snapshot in previous slide.

•No activity on AVST interface

•Tx_st_ready is low

•PMA lock is high reset status are ok from the HIP

•We are not in a state where application can run as the tx_st_ready is always low.


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5 Replies

Hi @FPGA3 


Please check the following reset signals with Signaltap (see attached). Thanks.

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I checked it, This signal is low in signal tap.

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As suggested, I tried driving the npor with the pin_perstn signal but no change in the output.

 Me and Harris had a second call after few mins again and here is the conclusion from the call.

Few pointers that we discussed in the second call after I tried the experiment quickly.

  1. The current reset status that we captured in the signal tap is correct. Since the signal is active high and not active low. So original output was correct.
  2. Since the design has already enumerated the it is out of reset.
  3. Reviewed the IP configuration and the Tool version with Harris.
  4. I have attached the ppt with design description and the signal tap file with all the signals captured value as requested by Harris
  5. Harris to review the files and the ppt and get back to us with nest steps.


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As mentioned by Harris:

I checked the signals in .stp file, they were probed in post-fitting mode which was not correct way since signals might be no exist after full compilation. After I changed to pre-synthesis way, we can find PCIe HIP works well like ‘tl_cfg_xxx’ are toggling and ‘tx_st_ready’ is high. Currently, the problem is in user logic, why user logic doesn’t send out packets on AVST TX interface. Customer will need to debug the user logic next.


With that, I will now transition this thread to community support. If you have a new question, feel free to open a new thread to get the support from Intel experts. Otherwise, the community users will continue to help you on this thread. Thank you.

Best Regards,
Richard Tan

p/s: If any answer from the community or Intel support are helpful, please feel free to give Kudos. 

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