TPS65987-90EVM: Maximum Resolutions for DP Alt Mode

Jake Swensen

Part Number: TPS65987-90EVM

Hi,

I've read through some of the documentation for the TPS65987 and the related EVM but I can't seem to find anything about supported resolutions for different configurations while using the DP alt mode.

My problem is that I'm using a Dell U2715H to test different features of the chip, but when I use the EVM as an UFP with the 10G Expansion EVM I don't get the full resolution of the monitor. The monitor supports 2560x1440 but when attached to the EVM I can only select 2048x1152 from the OS. Is there a limit to the chip or do I need to change some settings in order for it to work at full resolution?

Thanks!

over 6 years ago

0 Ghouse Mohiuddin23 over 6 years ago

TI__Expert 8000 points

What is the version of the 10G Expansion EVM that you are using? You will need ACS 002C version for this. I have found that on some of the EVMs The C6, C7, C8, C9 has not so good 0ohm resistors populated on it which you degrade signal integrity of the EVM.

Best is to move to TPS65987EVM instead of TPS65987_90EVM. TPS65987_90EVM is now EOL.

0 Jake Swensen over 6 years ago in reply to Ghouse Mohiuddin23

Prodigy 40 points

Thanks for the quick response!
My apologies, I must have copied the wrong text thinking it was the same. I do have the TPS65987EVM. The label on the expansion sink board is 10G_EXPANSION_EVM PSIL068.

0 Ghouse Mohiuddin23 over 6 years ago in reply to Jake Swensen

TI__Expert 8000 points

Can you send me picture of your boards, and picture of your setup?

0 Jake Swensen over 6 years ago in reply to Ghouse Mohiuddin23

Prodigy 40 points

Eval board setup

Eval board attached to Dell Monitor

Dell monitor without eval board

Project file used on eval board

ti-port-controller-test.pjt

0 Jake Swensen over 6 years ago in reply to Ghouse Mohiuddin23

Prodigy 40 points

Hi Ghouse Mohiuddin23,
Any ideas what's going on here?

Thanks!

0 Ghouse Mohiuddin23 over 6 years ago in reply to Jake Swensen

TI__Expert 8000 points

Jake,

You should check if the Expansion board is correct revision ACS002C

One other thing you can also try and do is, in your project file you can look for Display Port Capabilities (0x51) register and uncheck Multifunction Preferred bit.

Theory here is that the AUX training is failing for higher resolution. There are number of things this can cause signal integrity issues, ie. cable lengths, USB-C cable etc.

When training fails for higher resolution, it will drop to lower resolution.

Interface

Interface forum

TPS65987-90EVM: Maximum Resolutions for DP Alt Mode