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JLee25
Novice
150 Views

HDMI Long Lock Time

Hi,

I am facing the Rx long lock time issue on HDMI 2.0 resolution.

I am using Cyclone 10 GX + Quartus 19.2.

 

Do you know how to reduce it?

 

Thank you!

 

BRs,

Johnson

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5 Replies
Deshi_Intel
Moderator
113 Views

Hi Johnson,

 

May I know are you using Intel HDMI IP or your own HDMI IP ?

 

Are you referring to Intel HDMI sink "locked" or "vid_lock" issue ? Some lock scenario example as below.

  • Have you ensure you are sending all valid HDMI data ?
  • If user is sending invalid control data, then the LOCKED port from the HDMI RX core will be deasserted.
  • If user is sending valid control data, but invalid Data Island, then they will see LOCKED port asserted but VID_LOCK deasserted.
  • locked [2:0] should have 3 bits. Do you see different result within these 3 bits ?
  • Does upgrading to latest Quartus version helps to resolve issue ?

 

 

Have you isolate the issue to find out under what operating condition that you observe slow lock time ?

  • Like does it has dependency on certain video resolution change ?
  • Does reducing video resolution helps to see if this issue is related to signal integrity concern ?

 

Finally, have you isolated whether the bottleneck resides in HDMI IP, or PLL or transceiver channel ?

  • Did you probe PLL lock, transceiver CDR lock or rx_ready signal and compare with HDMI lock status ?

 

Thanks.

 

Regards,

dlim

JLee25
Novice
113 Views

Hi Dlim,

Thanks for getting back.

 

I am using Intel HDMI IP and the the long lock issue was mentioned on,

https://www.intel.com/content/www/us/en/programmable/documentation/ezu1511767661589.html

 

 

I noticed this in my latest compilation resolution, same hardware and same source...

In my previous test, there's no long lock issue..

 

FYI!

 

BRs,

Johnson

 

Deshi_Intel
Moderator
113 Views

Hi Johnson,

 

Thanks for pointing out the long lock time limitation in C10 GX HDMI design example doc.

 

I want to clarify further with you first before I check with Intel Engineering team on long lock time issue fix update.

  • May I know are you using just HDMI IP or HDMI design example that encounter this long lock time issue ?
  • V19.2 : you countered long lock time issue
  • You also mentioned previous Quartus version doesn't face this issue. Can you let me know which previous Quartus version is working fine ?

 

Thanks.

 

Regards,

dlim

JLee25
Novice
113 Views

Hi Dlim,

 

For this issue, I am using HDMI IP on custom board and Quartus Pro V19.2.

 

I used to test HDMI reference design on C10 GX EVB, Q18.0.1..

 

I am asking because I noticed the Rx is always work with 1080p but not UHD...

And I want to clarify this issue is coming form the IP or Signal Integrity.

 

Thank you!

 

BRs,

Johnson

Deshi_Intel
Moderator
113 Views

Hi Johnson,

 

Ok, thanks for providing more info but let's not mix up the 2 issues here.

 

  1. Regarding UHD is not working issue
  • There are a lot of factor that may impact the functionality like Quartus design timing closure, board signal_integrity, transceiver link tuning and etc
    • You need to slowly isolate the issue first
  1. Regarding HDMI slow lock time issue
  • For this, I have clarified with Intel Engineering team. I get a better understanding now and sorry for the confusing design limitation write up in the HDMI design example doc
    • What the attached design example statement screen shot means is
      • using HDMI IP only, it won’t achieve fast lock time
      • As a workaround, user can follow HDMI design example to use the symbol_aligner.v design to improve the lock time.

 

Thanks.

 

Regards,

dlim

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