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Last Post 03 Jan 2009 02:02 AM by
Interfacing to LCDs
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New Member

New Member

10 Apr 2008 03:45 PM
    We've tried to make it as straight-forward as possible to interface new displays to our products. LogicLoader 2.x has some new features to allow for this.

    If you are looking to interface a display, this document should help you along the process. You will need to be up to speed on how the specific LCD controller operates and how the adjustments to its registers affect the display timing.

    Integrating Custom Displays with LogicLoader
    Application Note #298

    Interfacing LCD’s to Logic’s SDK Board
    Application Note #161

    -Mike A.

    New Member

    New Member

    10 Apr 2008 03:46 PM
    Another good application note, by a third party is this one from NXP's line of LH7xxxx ARM controllers (formerly Sharp).


    It is specific to the LH79520, but I think gives a good background on LCD connections.


    New Member

    New Member

    06 Jun 2008 11:30 AM

    I have interfaced LG Philips LCD to iMX31 LITEKIT. Its a 18 bbp VGA display.
    When I am trying to initialize display for 18bbp , LOLO gives message as
    'found no suitable display driver'. Can I use the config block to solve this problem, if yes,how should I proceed.


    New Member

    New Member

    06 Jun 2008 11:46 AM
    Are you using a standard display mode with this panel (1,2,3.etc) or trying to create your own? (The standard modes would only work if the timing is exactly the same) Also, your panel is 18 color bits, but this is different than bits per pixel. LogicLoader only supports 16bpp. The 18 bits is in reference to how many color bits (red/green/blue) that is mapped from the controller to the LCD. So, you have to use 16bpp in LogicLoader, which is what the frame buffer will be. The LCD controller than interrupts this data and puts it on the color hardware bits (signals). (The imx31 does support other bpp but we only support 16bpp in LoLo)

    Also, in LogicLoader we set up the interface to be 16 bits (5 red:6 green:5 blue). We do this because it maps well to 16bpp. If you wanted to do full 18 bits of color, you'd have to use a bigger 'bpp' setting in your frame bugger and that uses much more memory.

    So, how do you map 18 bits to 16 bits? (This is covered in several other posts in the discussion group also I believe)

    Based on the iMX31 SOM signal names. If you look at our base board schematics, There is a jumper option for Red 0 and Blue 0 of the LCD. By default, these are connected to LCD_R5 and LCD_B5 and not LCD_R0 and LCD_B0 of the SOM. If you just use the 60 pin connector on the SDK, you can connect the red and blue 0 signals to your LCD because we make this conversion below on teh baseboard.

    iMX31 18-bit
    LCD_R5 R5
    LCD_R4 R4
    LCD_R3 R3
    LCD_R2 R2
    LCD_R1 R1
    LCD_R5 R0 (conversion done on SOM-LV Kit Baseboard)

    LCD_G5 G5
    LCD_G4 G4
    LCD_G3 G3
    LCD_G2 G2
    LCD_G1 G1
    LCD_G0 G0

    LCD_B5 B5
    LCD_B4 B4
    LCD_B3 B3
    LCD_B2 B2
    LCD_B1 B1
    LCD_B5 B0 (conversion done on SOM-LV Kit Baseboard)

    New Member

    New Member

    03 Jan 2009 02:02 AM
    Im cross posting this question from Display Dev Kits forum, hoping that someone who has used a ADTFT/HRTFT can answer this:

    I have a Sharp LQ035Q7DH06 LCD which is a followup to the now discontinued LQ035Q7DB02. Standard 3.5" touch screen that LogicPD used to base its display kit on.

    My question is: did the imx31 SDK connect anything to the LCD's SPR pin. I notice that the SDK has a pin to drive LCD's SPL, but not SPR.

    Anyone know what connects to SPR ?

    Also, is there any documentation that gives a long form description of the SDK's pins?
    For example, I am interested in SDK pin 49, which is LCD_HRLP where can I find out what HRLP is, I'd like to know if this is equivalent to Sharp's LP pin (data latch signal).
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