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DS90UB949A-Q1: video timing

Shinji Tsuji
Genius 14089 points
Part Number: DS90UB949A-Q1

Hi team, 

I am considering to use DS90UB949 and DS90UB948 combination. 

Then I would like to know the dual link open LDI output from DS90UB948 video timing. 

I see oLDI output is Hsync/Vsync/DE format, but could you advise how exactly converted into below ActiveH/V, H/V frontPorch, H/V Sync, H/V backPorch?

HDMI input timing is as below.

Active area 1920 x 720, 63.6712Hz, 100.26MHz

Hfront : 75, Hsync : 20, Hback : 30, Hpol : P

Vfront : 10. Vsync : 20, Vback : 20, Vpol : P

Which of the following video timing is true for each(even and odd) oLDI output?

① Horizontal total: 1085 =ActiveH960+Hfront75+Hsync20+Hback30
Vertical total:770= ActiveV720+Vfront10+Vsync20+Vback20

② Horizontal total: 1022.5 =ActiveH960+Hfront37.5(75/2)+Hsync10(20/2)+Hback15(30/2)
Vertical total:770= ActiveV720+Vfront10+Vsync20+Vback20

regards,

  • 0
    TI__Genius 13230 points

    Hi Shinji,

    Shinji Tsuji said:

    Then I would like to know the dual link open LDI output from DS90UB948 video timing. 

    I see oLDI output is Hsync/Vsync/DE format, but could you advise how exactly converted into below ActiveH/V, H/V frontPorch, H/V Sync, H/V backPorch?

    The input RGB data is split into odd and even pixels starting with the ODD (first) pixel outputs D0 to D3 and then the EVEN (second) pixel outputs D4 to D7. The splitting of the data signals starts with DE (data enable) transitioning from logic LOW to HIGH indicating active data.

    Best Regards,

    Gil Abarca

  • 0 in reply to Gil Abarca Ramos
    TI__Genius 14089 points

    Hi Gil-san,

    Does Odd/Even pixel means pixels in Odd line and Even line, correct? (like interlace)

    I would like to know how video timing at HDMI input of DS90UB949 below is converted to HSYNC/VSYN/DE signal at the 

    output of DS90UB948 open LDI. 

    Does DS90UB949 and UB948 keeps below timing? 

    Hfront : 75, Hsync : 20, Hback : 30, Hpol : P

    Vfront : 10. Vsync : 20, Vback : 20, Vpol : P

    regards,

  • +1 in reply to Shinji Tsuji
    TI__Genius 13230 points

    Hi Shinji,

    Shinji Tsuji said:
    Does Odd/Even pixel means pixels in Odd line and Even line, correct?

    This means odd/even pixels not lines.

    Shinji Tsuji said:

    I would like to know how video timing at HDMI input of DS90UB949 below is converted to HSYNC/VSYN/DE signal at the 

    output of DS90UB948 open LDI. 

    Please check the 7.4.3 OpenLDI Output Frame and Color Bit Mapping Select section on the 948 to understand the process.

    Shinji Tsuji said:

    Does DS90UB949 and UB948 keeps below timing? 

    Hfront : 75, Hsync : 20, Hback : 30, Hpol : P

    Vfront : 10. Vsync : 20, Vback : 20, Vpol : P

    Yes, it should keep the same timing it receives. 

    Best Regards,

    Gil Abarca