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How to enable VGA support?

OTS
New Contributor I
1,586 Views

Hello,
I'd like to enable VGA support on graphics circuits from Intel but fail to do so.

First I set up a display mode using a generation x graphics standard:

  • clock generator speed = 152,857,142 Hz
  • image refreshing rate = 65 Hz
  • x.input drawing area size = 1,920 pixels
  • y.input drawing area size = 1,200 lines

So far, this works.

Then I'd like to disable generation x support (if necessary) and enable VGA support:

  • # disable output connector
    digital display port B control["digital display port B enable"] = false
  • # disable non-VGA plane
    display A plane control["display plane A enable"] = false
  • # disable timing control via generation x and enable timing control via VGA
    VGA display plane control["VGA display disable"] = false
    VGA display plane control["VGA centering enable"] = 00|b
  • # disable image pipeline
    pipe A configuration["pipe A enable"] = false
    wait until pipe A configuration["pipe state"] == false
  • # disable clock generator (digital phase-locked loop)
    DPLL A control["DPLL A VCO enable"] = false
    DPLL A control["DPLL A external clock buffer enable"] = false
  • # disable clock generator control via generation x and enable clock generator control via VGA
    DPLL A control["VGA mode disable"] = false
  • # enable clock generator
    DPLL A control["DPLL A VCO enable"] = true
    DPLL A control["DPLL A external clock buffer enable"] = true
  • # enable image pipeline
    pipe A configuration["pipe A enable"] = true
    wait until pipe A configuration["pipe state"] == true
  • # enable output connector
    digital display port B control["digital display port B enable"] = true

Now I would expect, that the clock generator speed changes to one of the VGA clock generator speeds:

  • 12,587,500|d Hz (25 MHz / 2)
  • 14,161,000|d Hz (28 MHz / 2)
  • 25,175,000|d Hz
  • 28,322,000|d Hz

But it doesn't. My oscilloscope says, that the speed remains at 153,374,233 Hz.

Does someone know the correct sequence to activate VGA support?

Thank you.

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Hugo_Intel
Employee
1,496 Views

Hello OTS

  

Thank you for posting on the Intel️® communities.  

  

We will move your question to the correct sub-forum, the team in charge will get back to you soon. 

  

Best regards,  

  

Hugo O.  

Intel Customer Support Technician 


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OTS
New Contributor I
1,386 Views

I am still interested, if anyone cares.

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