1 Reply Latest reply on Jan 25, 2012 6:02 PM by Kirk

    Question with IEGD 10.3 , 945GSE and LVDS display choices.

    tom.abcd Green Belt

      I am using IEGD 10.3 with a computer module that has a Intel Atom N270 processor and a

      945GSE graphics chip.  I have the bios setup for a LVDS display that is 1024 x 768 display at 60

      hz.  I have the port order for LVDS first then CRT second.

      I am running XP Embedded Service pack3.


      Going to Control panel -> Display->Settings-> Advanced->Display Config tab

      I can choose the Primary and Secondary Resolutions. 

      Display Config = LVDS (clone) CRT


      Primary Mode

      Resolution choices

      1024 x768 x 60

      640 x 480 x 85

      640 x 480 x 100

      800 x 600 x 70

      800 x 600 x 72

      800 x 600 x 75

      800 x 600 x 85


      So why are there no 60 hz choices for the 640x480 or the 800x600 resolutions?


      For the Secondary display (CRT) there are lots of choice including ones with 60hz at the low resolutions.


      On an older board running a older version of IEGD we did have the 60hz choices when driving the same LCD panel.


      The unit works when set at the lower settings (Window runs at the lower res and the graphic chip sizes it up for the panel) but was surprised by no 60 hz choice.




        • Re: Question with IEGD 10.3 , 945GSE and LVDS display choices.
          Kirk Brown Belt

          This is pretty strange.  I am not aware of a change to our handling non-native resolutions on an LVDS.  What it kind of looks like is that you have not set your LVDS port for "fixed timing" on the LVDS port setting page of CED under "Panel Settings Page", and the driver is trying to keep options that fit the panels declared horizontal frequency which is higher on lower resolutions.. This is something we do to allow the display support flexibility we have on the embedded drivers.  When the horizontal resolution stays the same, and the resolution drops, the vertical frequency goes up.


          My recommendation would be to set the "Fixed Timing"  which allows the driver to keep the output at the 1024 x 768 resolution that your LVDS panel can ONLY run at, and then use upscaling to allow lower resolutions to be displayed on the higher resolution panel.


          On the main LVDS config page you likely will need to set "Use user-defined DTDs" as most LVDS panels do NOT support EDID and the driver needs to know what timings to use to support your panel.  You leave "Use driver built-in standard timing" to allow the driver to offer Windows the lower standard resolutions even though technically the LVDS panel itself cannot accept those resolution.  This is where Fixed timing and upscaling let us handle those non-native resolutions.


          Once you lock all this down, it is my experience that you should get what you expect.  If not, then something really unintended has happened with the driver on the 10.3 release and we will need to look at it.