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TPS65982: Display Port Video bypass from TPS65982+HD3SS460 at USB-C port 1 to USB-C Port 2 TPS65982+HD3SS460

Part Number: TPS65982
Other Parts Discussed in Thread: HD3SS460, , TIDA-01243,

Hi,

we are trying to get video through our device from USB-C Port 1 to USB-C Port 2.

Both ports are identical. They contain TPS65982+HD3SS460.

Both ports configured from TPS65982 application customization tool to support Display port (see image).

Video signals connected from Port 1 to Port 2 (after HD3SS460) in next way:

Port 1 / Port 2

LN0 (p) -> LN3 (p)

LN0 (n) -> LN3 (n)

 LN1 (p) -> LN2 (p)

LN1 (n) -> LN2 (n)

 LN2 (p) -> LN1 (p)

LN2 (n) -> LN1 (n)

 LN3 (p) -> LN0 (p)

LN3 (n) -> LN0 (n)

Please help to find out why we can't pass video through our device?

Is something wrong with configuration?

Can we get some support from TI?
We are making device that soon should be in mass production and this issue is completely blocking all future work.

We are using MacBook Pro as video source and LG Ultra Fine monitor.

--

Best Regards,

Sergii

  • hi Sergii,

    Sorry for critical delay, everything you are doing seems correct. Let me further assist you till issue is solved.

    The first step is to make sure the correct MUX ctrl bits on the SS MUX are mapped to the correct 82's GPIO's => go to ‘GPIO event map’ register 0x5c in the config tool. Plug event, AMSEL event, Port Connected CC2 (Cable Orientation Event) need to be mapped correctly in order for the SS MUX to configure the correct signaling. note: also HPD (TX/RX) is GPIO4.

    I attached a couple screenshots in a document to illustrate this. Please let me know the outcome of testing the SSMUX control GPIO config.    

    HD3SS460_GPIO_config.docx

    Thanks

  • Hi Jeffrey,
    thanks for the quick answer! Yes, lets make this feature works :)
    I have correct configuration, same as you proposed. Also when i solder wires to Display port connector (istead of USB-C port 2) - i can get video out of MacBook, up to 5K.
    So, looks like MUX is controlled correctly and HDP (TX/RX) set to GPIO 4.
    MacBook is detecting the monitor (it detect that LG UltraFine is connected, but video is absent), and saying that monitor is attached, but MacBook became to be very slow.... I can observe at oscilloscoupe that HPD signal has frequency 3 Hz - I assume that due to that 3Hz MacBook has some issue with perforance.

    When i am connecting external monitor via Display port wires (Samsung 4K) - everything works perfect.
    Any ideas?..
    Best regards,
    Sergii

  • Hi Sergii,

    To confirm and further claify, the connections you are making are the same as the screenshot below (found in the HD3SS460 datashet pg.17 )?

    note: SBU1 and SBU2 are crossed.

    note: this is for pin assignment C and E not pin assignment D

    Thanks

    Jeff

  • Hi Jeff,

    why SBU1 and SBU2 are crossed? I think crossing is needed if USB-C cable inserted with 180degree rotation - than we will have polarity event

    Look, i have 2 USB-C MUXes like this:

    Than, I have made connections of 2 ports like that:

    In that case I am able to detect monitor (looks like AUX lines works OK - I could get parameters of the monitor) but i can't get video out. 

    Also i have tried to solder wires directly from Port1_DP to Port2_DP - without MUX1, and situation is the same.

    So, please confirm that I have to connect Lane 0 Source to Lane 3 Sink and so on.

    I also have tried to connect Lanes like that: LN0 to LN0, LN1 to LN1, and so on.. But same result - I can detect Monitor and parameters of it at MacBook, but no video.

    Also, do you know, LG UltraFine monitor, is it works in USB-C mode or only as Thunderbolt 3? I am afraid that it is not working due to that/

  • Hi Sergii,

    I see, thanks for clearing this up. Also thanks for supplying a beautiful diagram of your MUX connections. I will verify your lane connections are correct and also find out about the UltraFine monitor. I will update you in less than 24 hrs.

    Thanks
  • Hi Sergii,

    I attached a word doc to answer your questions. Please let me know if I helped you solve your issue or you have any more questions!

    port to port DP connections.docx

    Thanks

  • Hi Jeff,

    thanks a lot! Will try to check it right now.

    Thanks for comment about USB 3.0 P/N swapping. It was done at TI board that we have - EVK TIDA-01243 ;) And than i found that USB 3.0 standard allows to swap P/N  signals (only between the pair RX or TX). I also found it somewhere at TI forum.

    USB 3.0 part works OK in our project.

    I will check video connection and back to you :)

    --

    Best regards,

    Sergii

  • Hi Jeff,
    unfortunately - nothing changed. Video doesn't work.
    MacBook detecting that monitor ids presented and show that everything is ok, but video is absent.
    I have tried to check LG UltraFine monitor and Samsung 4k via usb-c to Display port cable - same results...
    Only 1 monitor was connected at same time.
    Any ideas?
    Do you have any EVK that could pass video from USB-C to another USB-C?

    Best regards,

    Sergii

    p.s. - PD IC configuration file

    PD_PORT1_no_source_TI.zip

  • Hi Sergii,

    Dont worry we will get this working. I attached a word doc with a few suggestions. Please let me know of any updates!

    DP_debug_ideas_QA_e2e.docx

    Thanks

  • Hi Jeff,
    thanks for the answers,
    some answers: I have tried to set "F" Pin assignment just for the test. It doesn't work without it too. I am using 2.12 config tool. So, i will try to update and check again. About Display Port signaling - there was also DP 1.3 there, and i've decided to try with "unspecified".
    I will check my USB 3.1 lines again to understand what is wrong.
    I already have communication between the MacBook and Monitor via my board (AUX data is OK, HPD signal available), so i have an issue in latest step - no video :)
    Can you please provide a link to your "82 EVM" ?

    Can you provide a links to schematics of that boards?
    --
    Best regards,
    Sergii

  • Hi Sergii,

    Sounds good!

    This is the link for the 82 EVM
    www.ti.com/.../tps65982-evm EVM&tisearch=Search-EN-Everything

    The link for the 'TPS65982-EVM Design Files' (can be found in the link above about half way down the page)

    If you require the DP-EXPANSION board sch let me know.

    Thanks
  • Hi Jeff,
    I have 2x of this EVK :) can you please share sch for DP expansion board? Is it possible to buy it?
  • Hi Jeff,

    any news? I found SCH and checked that I have correct schematic connection. Will order kits and proceed with them, looks like there are something wrong in configuration (at our board)

    --

    Regards,

    Sergii

  • Hi Sergii,

    Sorry for the late reply.

    The DP expansion board can be bought here:

    www.ti.com/.../DP-EXPANSION-EVM expansion board&tisearch=Search-EN-Everything

    If you think the issue is in the configuration I will ask my team to look into your project file. I will update you asap with anything we find.

    Thanks

  • Hi Jeff,

    yes, i already found that board and found that there are 2 different EVKs - for x82 and x86 ICs. We have x82 kits, without DP port.

    We have ordered 2x x86 kits + DP expansion board to test solution with MacBook and LG monitor.

    It will be good if your team will look into the project file.

    --

    Best regards,

    Sergii

  • Hi Sergii,

    I just wanted to update you, I am still looking into your pjt file with the team. I noticed the pjt file you sent me does not have a low region included. Can you send me the low region bin that you are using the pjt file with?

    note: When using the x86 EVM I had to change GPIO0,3,14 to 'plug event', 'AMSEL', and 'CC2 orientation' GPIO events respectively.

    Thanks

  • Hi Jeff,
    I got kits and already made some testing, unfortunately that doesn't work..
    I have 2x TPS65986 kits + Display port expansion pack.
    1 PCB configured to UFP (0010 configuration)
    2nd PCB configured as DFP (1000 configuration)

    MacBook is able to detect that monitor is connected, MacBook could see LG USB Audio, and could see LG monitor, but video is absent and MacBook became to work too slow...

     _
    --
    Regards,
    Sergii

  • More info,
    I've made 2 additional tests:
    1) USB-C monitor connected via TPS65986 and DP board to Toshiba Laptop with miniDP connector - it works OK.
    2) DP monitor, connected via TPS65986 and DP board to MacBook USB-C - works OK too.
    So, looks like LG monitor doesn't want to work via USB-C to DP - USB-C link. Any suggestions?...
    --
    Best regards,
    Sergii
  • Hi Sergii,

    To clarify, you are using only 1 EVM for the two additional tests?
    What USB-C monitor did you use for additional test #1?  is that the same as the LG monitor?

    - try using a different monitor

    - try using a windows laptop.

    - try using config ID 5 instead of ID4 for the UFP.

    - You can also try to update or reinstall your graphics driver on your laptop.

    I would like to see a lecroy PD trace of the failing case too.

    Thanks

  • Hi Jeff,
    - I have only 1 USB-C monitor - LG. So, i've used it for all tests. I have 2 of them and both works in same way.
    - I have no windows laptop with USB-C
    - yes, already did that - doesn't help ( try using config ID 5 instead of ID4 for the UFP.)
    - ok, will try to do that.
    I will be out of office 2 weeks and than back.
    Have you tried to do same test ? with macbook + usb-C monitor and this EVK boards?
    --
    Best regards,
    Sergii
  • Hi Sergii,

    Sounds good, I was able to locate a typeC-monitor and will let you know the outcome of testing asap.

    Thanks
  • Hi Jeff,
    any news?...
    I am still not able to pass video via TI EVK...
    --
    Regards,
    Sergii
  • Hi Sergii,

    Currently we are seeing something simiar to you. In the past this has worked with the ultrafineLG, the only difference now is the version of the tool and possibly the template. 

    The laptop sees HPD and enters DP mode however no video. We are simply using one 86 connected to the type-C-monitor with a type-C to type-C cable, and the laptop connected to DP source expansion board with DP to DP mini cable. My next step is to probe GPIO0,3,14 to see whats going on. Also see if there any inconsistency with PD messaging. Theres some delay in testing because the type-C monitor I need to use has been occupied but I will stay late/early so I can use it. I will let you know the results later today or tommorrow.

    Thanks

  • Hi Sergii,

    Wanted to update you, I have tried changing GPIO event mapping and DP capabilities register and have gotten different, unsuccessful results everytime. I will bring my team in on this and let you know of any updates.

    Thanks
  • Hi Sergii,

    I found this e2e post of a similar DP issue using LG type-C monitor, x982, and the HD3SS460. This may or may not help you so I will keep updating you of my progress with this issue.

    Thanks

  • Hi Jeff,

    thank you for the inputs. In my case TPS65982 + LG works OK)

    So, i just need to pass video from 1 USB-C to 2nd USB-C)

    Will wait an answer from you, thank you for the support.

    --

    Best regards,

    Sergii

  • Hi Sergii,

    I was able to pass video to the typeC monitor using one 86EVM and a DP source EXPANSION board. My Dell laptop was the source and connected to the DP EXPANSION board with a miniDP to DP cable. I connected the EVM to the typeC monitor with a type C to type C cable. 

    I used config ID2 => SW(1,2,3,4) = SW(0,1,0,0)

    Also make sure the following resistors on the DP-EXPANSION board are not populated:

    R2_BB, R3_BB, R4_BB,R5_BB (on top of board)

    R11,R12,R13,R14 (on bottom of board)

    These resistors are pull ups and pull downs for a voltage divider on AUX P/N and config1 and config2.

    Let me know if you are able to do this (with only one EVM)...then you can add in the second EVM.

    Thanks

  • Hi Jeff,

    thank you for the update,
    yes, i was able to do that too :) I have IBM PC with miniDisplay Port and it works OK with LG monitor.
    But when 2 EVM PCBs connected together - i am not able to pass video from MAC to USB-C -> kit1 -> DP cable -> kit 2 -> USB-C -> LG monitor
    --
    Best regards,
    Sergii

  • Hi Sergii,

    Is this block diagram correct?

    I am unable to find a mini-DP to Type-C cable however I can order a DP female to male Type-C adapter.

    Thanks

  • Hi Jeff,
    no,
    I have Display port cable between the kits, and USB-C cables to MAC and to LG. So, just swap them
    --
    Regards,
    Sergii
  • Hi Sergii,

    Try this,

    Its weird because the Source/DFP is the UFP_D and the sink/UFP is the DFP_D. This can probably still work with different configID however.

    Are you able to get this to work?

  • Hi Jeff,
    that is exactly that i made. I have checked that one more time today and it is not working. In that case MAC can't even detect LG monitor.
    But when i changing configuration of DFP from config 0 to config 4: 0010 - MAC is detecting LG, but video is absent. And MacBook is working very slowly in that case.
    --
    Regards,
    Sergii
  • Hi Sergii,

    I might have to obtain a LGultrafine monitor - let me ask my team for suggestion and I will let you know the update by the end of today.

    Thanks,

  • Hi Jeff,
    ok, thanks. Which USB-C monitor works OK with your suggested case ?
    --
    Best regards,
    Sergii
  • Hi Sergii,

    I was using a Dell S2718D. I will let you know if or if not I will be able to get an LG.

    Thanks
  • Hi Sergii,

    I don't follow what you are trying to do. From some of the previous posts it looks like you want to do a DisplayPort pass through from one Type-C port to another Type-C port. Is this correct?

    Could you clarify what Port 1 and Port 2 will be doing from the video source or sink perspective. A DFP_D would be a source of video and an UFP_D would be a sink of video.

    UFP_D and DFP_D configuration is not fully supported by any release systems. On the configuration above UFP_D can either be Pin Assignment C & D or just E. Pin Assignment E is intended for DP Dongles. You can refer to the DP over Type-C spec section 3.7.

    Could you take a picture of your exact setup? Which MacBook are you using?

    Jacob
  • Hi Jacob,

    I am making device, where i need to be able to pass video from USB-C (macbook) to USB-C (LG monitor). We have TI USB HUB, with USB-C upstream to MacBook, and USB-C downstream to LG monitor. I got PCBs where everything is connected according to the guides, but we can't pass video. Than I have ordered 2kits, that were suggested by Jeff. And made tests.

    Test setup was done according to Jeff's picture:

    I am using MacBook Pro 2016 and LG UltraFine monitor, see below.

    As you can see - Mac is detecting the monitor, detecting type of the monitor, but starting to work very slowly (I have detected that USB-C monitor changing HPD signal all the time - it was checked at EVK - with 5Hz frequency. So, 5 times during 1 second LG monitors says that it s connected and than disconnected). And video at LG is absent. I also have tried to connect kit with USB cable - in that case Mac is detecting USB HUB that is builded into the monitor. But still no video. I have tried all possible UFP/DFP configuration for the EVK by jumpers. And i didn't changed original FW at kits.

    I really hope that you and Jeff will help me to get this working :)

    Best regards,

    Sergii

  • Hi Sergii,

    Jacob is OoO for this week just to let you know. My only option I see to help you without him is to locate a LGultrafine. Which I am on the look for. Anyhow I will update you with that result as well as more help from Jacob asap.

    Thanks
  • Hi Sergii,

    Are you required to connect the 2 EVM's this way? Are you able to get video to pass by connecting the EVM's the regular way? How do you propose we tackle this issue? what do you think the root of the issue is?

    Thanks
  • Hi Jeff,

    ys, i need to connect 2 EVMs in this way because I need to pass video in our device from USB-C to USB-C ports.

    When I am using EVMs in regular ways: USB-C to DP monitor or DP output to USB-C monitor - everything works OK.

    I think that it is something with the protocol. Looks like MacBook is detecting the USB-C LG monitor via AUX lines and starting to work by using Thunderbolt protocol with it.

    So, my guess, that there is something with the protocol there.

    --

    Best regards,

    Sergii

  • Hi Sergii,

    Can you send me any of the following for the failing case?

    - Lecroy PD message trace
    - I2C dump of all the registers for both ports before and after failing case? or screenshot/'snapshot' Display Port Status (0x58) and configuration (0x51) registers
    - Scope shot of AUX_P/N and HPD signals on both source and sink during failing case

    Thanks
  • Hi Jeff,
    I've got another USB-C monitor - ASUS MB169 and it works OK with 2 EVK boards. So, it is some issues with LG monitor, not with TI ICs.
    Thanks for the support!
    --
    Best regards,
    Sergii
  • Hi Sergii,

    YAY! great news! Thanks for your patience throughout and also thanks for letting me know the issue was the monitor.  

    let me know if you have any more questions I would be glad to help you out :)

    Thanks