DS90UB949A-Q1: lose remote control of DS90UB948

Merlyn

Part Number: DS90UB949A-Q1

Hi，

1.Our HW setup is : DS90UB949A----(2-lane twisted STP)-----DS90ub948----(dual-link LVDS)-----TFT LCD(1920x720)

2.Experiment results:

(1)LCD can show normal test pattern(1920x720 @ 60fps) after initiated DS90UB949A, and remote control on DS90UB948 works fine.

(2)When host processor output HDMI source to DS90UB949A with a TMDS freq of 90MHz(read from REG[0x5F]), remote control works fine.

(3)When host processor output HDMI source to DS90UB949A with a TMDS freq of 118.8MHz(read from REG[0x5F]),lose remote control on DS90UB948

(4)check REG[0x5A] of DS90UB949A is 0xCD, REG[0x1C] of DS90UB948 is 0x3B. It seems dual-link FPD-link is correct.

Question:

(1)Does TMDS freq above 105MHz cause this issue? In dual-link FPD-LINK mode, maximum value of REG[0x5F] is 210MHz?

(2)Any other items we need check against?

over 3 years ago

0 Shu Huang over 3 years ago

TI__Mastermind 18046 points

Merlyn,

I will look into this and get back to you in 2-3 business days.

Best,

Shu

0 Shu Huang over 3 years ago in reply to Shu Huang

TI__Mastermind 18046 points

Hi Merlyn,

Since the 948 can only go up to 192 MHz in dual link, that would be the highest frequency read by REG[0x5F].

Do you have access to the Errata for the 949 and followed the steps on that document? If not, your local TI-FAE should be able to help get access to that document. The Errata has some very helpful set up steps that keep issues to a minimum.

Best,

Shu

0 Merlyn over 3 years ago in reply to Shu Huang

Prodigy 80 points

Thanks for your help.

This issue has been resolved. Hardware deficiency in SERDES link has been found, and link bandwidth was affected!

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DS90UB949A-Q1: lose remote control of DS90UB948