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OMAP-L138 LCD controller

Prad
Expert 1125 points
Other Parts Discussed in Thread: OMAP-L138

Hi,

This is a basic question about OMAP-L138 LCD display controller.
How can I check whether a particular LCD module is supported by OMAP-L138's
LCD controller and what are the main things to be considered?

Our LCD module has this kind of description

General Description:

*Driving Mode: Active Matrix.
*Color Mode:
  12 bit/pixel: R(4), G(4), B(4)
  16 bit/pixel: R(5), G(6), B(5)
  18 bit/pixel: R(6), G(6), B(6)
  24 bit/pixel: R(8), G(8), B(8)
*Driver IC: HX8358, COG Assembly

*Interface:
  MIPI-DBI 8-/9-/16-/18-/24-bit MPU parallel interface.
  MIPI-DBI Serial data transfer interface.
  MIPI-DPI 16-/18-/24- data lines parallel video (RGB) interface.
  MIPI-DSI Lanes 1 or Lanes 2 mode interface

Thankyou and Regards

  • 0
    TI__Mastermind 43875 points

    Prad,

    I think you should be OK with this LCD. OMAP-L138 supports active matrix raster mode which is the same as MIPI-DPI 16 parallel RGB.

    I could not find any information on the HX8358 so could not check the exact timings, but I believe you should be OK.

    If possible check the HX timing diagrams against the timing diagrams in the L138 datasheet at http://focus.ti.com/lit/ds/symlink/omap-l138.pdf

    In particular, look at figure 6-62.

    Kind regards,

    Steve

  • 0 in reply to Steve Clynes
    Expert 1125 points

     

    Hi Steve,

    Thanks for the support.

    There was one timing chart for DPI inteface(HX8358) as shown below,

    I think this is OK against OMAP-138 LCD timing chart.

    Regards.

    Prad

     

     

  • 0 in reply to Prad
    Expert 1125 points

     

    Hi,

     

    I am still confused in choosing the right LCD module which can be used with OMAP-L138.

    There are few more candidates(TFT LCD Modules)LQ035Q7DB03 and T-55149GD030J-MLW-AJN.

    I think OMAP-L138's LCD controller support these TFT LCD modules

    through Raster Controller(Active (TFT) Color mode).

    I want to choose the best of three.

     

    Thankyou.

     

     

     

  • 0 in reply to Prad
    TI__Mastermind 43875 points

    Prad,

    I don't think the Sharp module is compatible since it requires some additional timing signals. These signals could be generated externally with delays etc... but I don't think it is directly compatible.

    The Optrex device looks like a better match since it has a mode which simply takes h-sync, v-sync, enable and data. The only thing I am not sure about is the enable signal polarity. On OMAP this is programmable but I do not know about other devices.

    BR,

    Steve

  • 0 in reply to Steve Clynes
    TI__Mastermind 43875 points

    Sorry, I meant to say on OMAP3 the enable signal polarity is programmable. I am not sure about L138.

    BR,

    Steve

  • 0 in reply to Steve Clynes
    Expert 1125 points

    Hi Steve,

    Thankyou,

    Regarding Sharp module, the OMAP-L138 EVM from Zoom is also using a LCD from Sharp LQ036Q1DA01,and the timing chart of this LCD is similar to LQ035Q7DB03.

    Since there is no reference design I don't know whether it is using any external signals.

    Regarding enable signal polarity in OMAP-L138 LCD controller there is a bit called "BIAS" in LCD Raster Timing Register to change the polarity of LCD_AC_ENB_CS(AC Bias). SPRUFM0A(page 54).

    Please let me know if there is anything else to be considered.

     

    Regards.

    Prad.

  • 0 in reply to Prad
    TI__Mastermind 43875 points

    You are correct rergarding the similar timings.

    I will need to review the Zoom schematics to see how the additional signals are being provided (if at all).

    Given this information though, I think it should be safe to use either of the LCDs you originally specified, but check the connectivity for the Sharp LCD.

    BR,

    Steve