TPS65987EVM: TPS65987EVM problems

Hello Victor,

For your three problems:

1. I am not sure what lines you are looking at. I2C2 (which is used for FTDI) has a pullup, which is not reflected in the scope shot. Also,  I2C2 is only used in debug mode through the GUI for the EVM. 

2. There could be some equalization issues occurring when the phone is driving the super speed lines. You could try doing 4 lane DisplayPort if your phone can support that. 

3. Check to see if GPIO21 is set to Barrel Jack Detect Event. If it is not, enable it. This will check to see if the barrel jack has been connected and should enable a power role swap when it is.

Thanks,

Emma

Hello Emma,

this is my reply from customer:

1. I2C(which is used for FTDI) has a pullup, which is not reflected in the scope shot. Also,  I2C2 is only used in debug mode through the GUI for the EVM.

As can be seen in the Scope picture it is not a problem of pullups. You can see in a train of clocks that for some bytes it is 3.3V amplitude and for some it is about 1V. I don’t have any explanation except bad IC.

May be it is easier and cheaper to send a new EVB.

1. There could be some equalization issues occurring when the phone is driving the super speed lines. You could try doing 4 lane DisplayPort if your phone can support that.

It is not a problem of picture through Display port . it is a problem of negotiation . you can see on the pictures that when I connect the laptop the led of the DP (d13) is lit even when DP cable is not connected to EVB.

On the second picture when the smartphone is connected the Led is off.

If the debug function was functioning I could capture the status and analyze it but unfortunately it does not function.

1. Check to see if GPIO21 is set to Barrel Jack Detect Event. If it is not, enable it. This will check to see if the barrel jack has been connected and should enable a power role swap when it is.

That solved this problem, thanks.

Hello Victor,

Glad to hear the GPIO event solved one of your issues.

I2C works through pull ups, so if the lines are not pulled up, the communication will not work. If I2C2 is broken, you should order a new board. Your I2C communication usually look like this on the TPS65987EVM. 

Thanks,

Emma

Thank you Emma,

regarding the second question my customer asked, can you please help me answer his comment(resending)?:

1. There could be some equalization issues occurring when the phone is driving the super speed lines. You could try doing 4 lane DisplayPort if your phone can support that.

a. It is not a problem of picture through Display port . it is a problem of negotiation . you can see on the pictures that when I connect the laptop the led of the DP (d13) is lit even when DP cable is not connected to EVB.On the second picture when the smartphone is connected the Led is off.

If the debug function was functioning I could capture the status and analyze it but unfortunately it does not function.

Hell ,

I have ordered a new board for the customer(TPS65987EVM) as you have advised,

He is still having the same issue with the display port function as it is working with the laptop but not with his smartphone.

It is a Samsung S10e and it works with any adaptor that is on the market but not with the TI board.         

The debug problem that was on the previews board is happening on the new one.

See attached project files.

Can you help me with this?

 tps65987 4th.zip

Thank you for the support.

Hello Victor,

Do you or your customer have a PD analyzer to read the PD messaging being sent between the phone and EVM? The first step for displaying video over Type-C is to negotiate and accept the display port alternate mode. In your previous post, you state "on the second picture when the smartphone is connected the Led is off". The purpose of this LED it to indicate that HPD (hot plug detect) has gone high. So the fact that this is not going high shows that a display port connection is established and HPD is not going high (cause for the display issue) or that their is no DP alternate mode negotiated between the two devices. Both would cause for the video not to display, and you need a PD analyzer to help isolate where the issue could be occurring.

This is the one I typically recommend customers use.

https://www.totalphase.com/products/usb-power-delivery-analyzer/

Hello Adam, 

Yes the customer has total Phase PD analyzer and attached are the captured negotiation of 3 scenarios

1. His Samsung S10e Smartphone with an Cypress based HDMI Dongle.
2. His Samsung with TI EVM with no DP output. (it looks there is no negotiation for DP at all)
3. MacBook Pro with the same EVM with same configuration with DP displayed .

 The configuration in the last post for checking.

samsung s10e with TI evm.zip

Hello Victor,

With the Samsung and TI EVM, the Samsung device never sends the VDM:Discover Modes message, so the DP alternate mode is never discovered and entered. With the MacBook pro and TI EVM, the MacBook does send this discover modes message, so the two devices are able to discover and enter into the DP alternate mode. I am having difficulties opening the Samsung and dongle file so I cannot review them fully, but if this test works, it is probably because the dongle is sending the VDM:discover modes message and the two devices are able to enter into the DP alternate mode.

Since the Samsung phone is the one acting as the DFP. it should be the one to send out the request for VDM alternate modes.

Hi Adam, 

My customer answered the following:

"

I have checked with another product which is based on Cypress component with the same Samsung S10e and it works. Here is the log file from cypress analyzer that succeeded to charge and send DP signals.

I can’t accept that with Cypress PD controller it works and with TI not.

 "

samsung usb lock.zip