DS90UB949-Q1EVM: Computer HDMI out to DS90ub949-Q1EVM to DS90ub948 LVDS 1920*720 Screen display anomaly

Hi TI Team,  

ds90ub949EVM display computer HDMI  is 74Mhz,1280*720 video

Customer Screen is 1920*720 24Bit RGB

1,Computer HDMI output to DS90ub949EVM to DS90ub940 mipi to IMax6 to Screen, Display normaly

2,Imax6 LVDS output to DS90ub947 to Ds90ub948 to Screen,Display normaly,

But,

Computer HDMI output to DS90ub949EVM to DS90ub948 to Screen, Display anormaly, As attachment 0x22 no set 24bit Video picture

If, I set ub948 0x22(2) to 18bit Video,Display normaly (but the screen is dark),As attachment 0x22 set 18bit video picture

Qustion:

A, Why Computer HDMI output to DS90ub949EVM to DS90ub948 to Screen Display anormaly, Need set ub948 to 18bit Video

B, Computer HDMI output to DS90ub949EVM to DS90ub948 to Screen Display,if need other set on ub948?

thanks!

Hi Ti team,

      We test Imax6 HDMI output 24RGB444 to DS90ub949 to DS90ub948 to Screen,

Then the same need set ub948 to 18bit Video ,display normal(but the screen is dark),if use ub948 24Bit RGB,then display anomaly.

How to do set the ub948 or ub949 ,then Imax6 HDMI 24RGB444 to ds90ub949 to ds90ub48 to Screen could dispaly 24bit RGB output?

thanks!

Jimmy,
I.MX6 output is RGB444?
can you explain what is "the screen is dark" and it is normal? thanks.
for the link between UB949 and UB948, no special setting is required for UB948. You can check the UB949 register status for further debug.

best regards,
Steven

Steven,

Yes,Imax6 HDMI output is 24bit RGB444

"the Screen is dark" and it is normal : The screen is dark and the drawing can be clear, it set ub948 to 18bit Video, as shown above

If you do not set ub948 to 18bit Video, use the default 24Bit Video to show that the drawing are blurred and can not be seen clearly, as shown in the figure above.

If We used Computer HDMI output to DS90ub949EVM to ub948 Sec,that's the same as above。

So, We want to know that if HDMI output 24Bit RGB444 from DS90ub949 to Ds90ub948, then Could ub948 can been output 24bit data or 18bit ?

Thanks!！

Steven,

Yes,Imax6 HDMI output is 24bit RGB444

"the Screen is dark" and it is normal : The screen is dark and the drawing can be clear, it set ub948 to 18bit Video, as shown above

If you do not set ub948 to 18bit Video, use the default 24Bit Video to show that the drawing are blurred and can not be seen clearly, as shown in the figure above.

If We used Computer HDMI output to DS90ub949EVM to ub948 Sec,that's the same as above。

So, We want to know that if HDMI output 24Bit RGB444 from DS90ub949 to Ds90ub948, then Could ub948 can been output 24bit data or 18bit ?

Thanks!

Jimmy,
most FPD-Link serdes has no video color space convert function. if the video source is RGB888, the display panel also should be set at RGB888. if RGB444 video source is used, the display side also should be set as RGB444 for correct display performance.
for your case, can you try the RGB888 in the UB949 side? it should be clear.


best regards,
Steven

Steven,

Customer feedback Imax6 HDMI output don't output RGB888, can output RGB444.So no try the RGB888 in Ub949 Side,thanks!

Jimmy,
many customers in the market use the combo "i.MX6 + UB949" solution , and don't have video format issue. can you please check it again? thanks.

best regards,
Steven

Steven,

     As above said,We used Imax6 +Ub949 to Ub940 also have no  issue,used Imax6 +Ub947 to ub948 also have no issue, but used Imax6+Ub949 to Ub948 have above issue.thanks!

You should check the I/f between UB948 and display panel video control chip, does the lane setting is correct?

regards,
Steven

also, RGB888 should be used. for infortaiment, NO RGB444 is used in the market.

best regards,
Steven