TUSB1064: Application issues.

Reed

Expert 1910 points

Part Number: TUSB1064

Tool/software:

Hi Team,

Using switch chip TUSB1064,
When connecting to a laptop, there is a problem of slow image output. Upon investigation, it was found that the switch and the KTM5000 DP to TMDS chip in the backend have undergone multiple handshakes. The USB 3.0 signal in the backend passes through a HUB chip, which does not experience multiple handshakes when using 5G firmware. However, when using 10G firmware, multiple handshakes occur, resulting in a long image output time. So, will the 10G signal of USB 3.0 affect the DP signal? And possible reasons for slow image production.

a. Hardware design framework:

b. On the left is the slow image output of HUB using 10G firmware, while on the right is the fast image output of HUB using 5G firmware.

c. schematic diagram.

7 months ago

0 Vishesh Pithadiya 7 months ago

TI__Mastermind 38885 points

Hi,

1) Are you able to send a full schematic? Its difficult to read and zoom in on the images provided.

2) We need to look into the root cause of the multiple handshakes. from my understanding this is just configuring the device to send data out, and the TUSB1064 should not play a role in this handshake. Is this correct?

3) When we only see the issue come up with 5G it makes me think that the 10G signal is not properly equalized, so link training takes longer to get an acceptable signal between the source and the sink. What is the EQ value used? are you able to increase the EQ and see what impact it has?

0 ?? ? 7 months ago in reply to Vishesh Pithadiya

Prodigy 50 points

ms0402-n011-000_v4_SWITCH.pdf

1)The schematic diagram is attached as an attachment.

2)According to the log of KTM5000, it is because of a single interruption of the DP signal that the rehandshake occurred.

3)According to your suggestion, how should I adjust the EQ value?

0 Vishesh Pithadiya 7 months ago in reply to ?? ?

TI__Mastermind 38885 points

Is it possible to probe the AUX lines and get an AUX log? I want to know why and what the interruption of the DP signal is.

I recommending increasing the EQ value. I'm not sure what the loss profiles of the board are. Are you able to populate this image with the losses of teach path?

0 ?? ? 7 months ago in reply to Vishesh Pithadiya

Prodigy 50 points

How do I get an AUX log？

The complete communication block diagram is as follows

0 Vishesh Pithadiya 7 months ago in reply to ?? ?

TI__Mastermind 38885 points

On the USB-C connector the AUX_P will be pin B8 and QUX_N will be pin B8. These are routed through the SBU1 and SBU2 paths. You will need to probe these with an AUX traffic monitor.

0 ?? ? 7 months ago in reply to Vishesh Pithadiya

Prodigy 50 points

See the attachment for AUX log.

aux+ktm5000 log.rar

0 Vishesh Pithadiya 7 months ago in reply to ?? ?

TI__Mastermind 38885 points

Hi,

Thanks for the quick response!

From what I see in the AUX log, the EDID is transmitted twice this will add some delay but should not account for the major delays you are experiencing.

In the KTM5000 log file I noticed that the audio format is chnaged three time

There seems to be an issue with the FEC which needs to constantly resync. The link training works and remains working until the DP source was disconnected. We can see some issue in the data being sent across in the decoded log. A majority of the data being sent is resent a few line later. Is there a way to test sending video without audio, or remove the FEC functionality?

0 ?? ? 7 months ago in reply to Vishesh Pithadiya

Prodigy 50 points

See the attached AUX log under normal conditions. Why does the 5G-10G firmware of USB3.0 affect the communication of KTM5000? What are the possible reasons

aux+ktm5000 log-5G.rar

0 ?? ? 6 months ago in reply to Vishesh Pithadiya

Prodigy 50 points

I did some experiments and found that there would be signal interruption only after the HUB reset under 10G firmware was completed. When using 5G firmware HUB reset, it would not affect the drawing. The attached picture is the USB3.0 signal under 10G firmware, is this the cause of the drawing interruption?

0 Vishesh Pithadiya 6 months ago in reply to ?? ?

TI__Mastermind 38885 points

Hi,

try replacing TUSB1064 on the bus and see if the no-image pulse still exists. I cant be sure on the cause yet.

Who is the SoC vendor? We may need to contact them as well.

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TUSB1064: Application issues.