• State Resolved
  • Locked Locked
  • Replies 5 replies
  • Subscribers 97 subscribers
  • Views 694 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

LCD Controller Compatibility

Stephen Lin40335
Intellectual 275 points
Other Parts Discussed in Thread: AM1808, OMAP-L138

Hi,

I am new to this LCD interface but would appreciate if someone can help me understand what types of LCD interface (in terms of user connector pins) can AM1808 processor connect to?  I am not talking about the board connector on the experimental board, which uses 60 pins connectors.  What I am talking about is the internal user interface pins defined by LCD manufacturer (such as 40pins, 45pins or 54pins depends on manufacturer... For instance, the experimental board uses Sharp LCD which uses 40 pins internally.) 

I read some wiki answer on this topic and found a LCD controller which gives more details ("SPRUFM0A" doc). In particular the LIDD controller which defines how AM1808's LCD controller can be compatible with different other types of displays.  However, it's not so clear to me how those pins can be mapped accordingly for different types of LCD?  For instance, what type of display is the one that currently connected to experimental board? 6800 family or 8080 family??

Please advise.

Thanks

 

  • 0
    TI__Mastermind 27585 points

    Have you registered your EVM on the LogicPD website? If so you will have access to the product information on the LCD displays as well as the schematics for the LCD display board.

    From the product brief, the Sharp part number is LQ036Q1DA01 for the 3.6" display.

    What kind of display are you trying to connect to? A LIDD or a raster-based? Active or passive? Are there any pins in particular that you are unclear on how they are mapped?

    Jeff

     

  • 0 in reply to jc-ti
    Intellectual 275 points

    Thanks, Jeff for the reply.

    We did register and received the schematic and BOM for the LCD. I even pull up the spec for that LCD as well. My question is not where to find them, but how to find another LCD display module to hook up to this EVM board. Or is it even possible?  Basically, we need 3.5" TFT LCD display, not the 4.3" TFT shown in Experimental kit, and we might need to sway from the Sharp manufacturer as well.  Since other manufacturer has different internal FLEX pins (in Sharp's case, it has 40 FLEX pins but was mapped to 60pins connector on the board), how do I connect another manufacturer's LCD module (for instance LG's 3.5" TFT) that has 45 or 54 FLEX pins?? 

    Is there any app notes on those compatibility issues and how one would need to change on the driver side to make it work as well?

    Thanks,

    Stephen

  • 0 in reply to Stephen Lin40335
    TI__Mastermind 27585 points

    We are currently developing an application note for LCD connectivity on this device. However currently we have a wiki page which contains applicable information from the OMAP2/3, found here: http://processors.wiki.ti.com/index.php/LCD_connectivity.

    In general the pins on the 60-pin header will map 1-1 with LCD panel inputs. For CMOS panels the pins can map directly, and for LVDS panels an LVDS translator will be necessary. Can you link to the datasheet for the specific panel you are considering?

    Jeff

  • 0 in reply to jc-ti
    Intellectual 275 points

    Thanks for the wiki page, it offer some insight into the LCD controller, but still not the whole picture (maybe I just need to wait for that apps notes you guys are working on....)

    As far as other LCD display such as LB043WQ1 from LG also uses 4.3" TFT, but has different FLEX pin (45pins) count than Sharp's 4.3" TFT (40pins). I am just puzzled on how those pins will be mapped directly (or thru LVDS)? Also, there must be restrictions on clock speed, refresh rate limit, timing requirement and voltage level...etc in order to find out the processor's compatibility toward other LCD modules?

     

  • 0 in reply to Stephen Lin40335
    TI__Mastermind 27585 points

    A good rule of thumb is Resolution * Frame_Rate * 1.3 < Pixel_clock. The pixel clock for the OMAP-L138 family of devices is 37.5MHz. You would have to check the LCD panel to see the voltage levels, but the L138 can output either 1.8V or 3.3V. If the panel is an LVDS panel then the translator will be required. Otherwise if it is a CMOS panel you can directly connect it.

    The panel you listed (LB043WQ1) is a CMOS panel, and you will find the signal names match up almost identically with the chip output pins.

    Jeff