Advantech ARK-3520L User Manual page 59

 Cdynmax Clamping Enable
Enable/Disable Cdynmax Clamping.
 Cd Clock Frequency
Select the highest Cd Clock frequency supported by the platform.
3.2.3.3 LCD Control
Primary IGFX Boot Display

Select the Video Device which will be activated during POST. This has no effect
if an external graphics present. Secondary boot display selection will appear
based on your selection. VGA modes will be supported only on primary display.
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