Main link video cannot be enabled until a proper video source has been
provided to the source core. Typically the source device wants to read the EDID from the
attached sink device to determine its capabilities, most importantly its preferred
resolution (and other supported resolutions if the preferred mode is not be available).
When a resolution has been determined, set the Main Stream Attributes in the source core
(0x180 to 0x1B0). Enable the main stream (0x084) only
when a reliable video source is available.
Important: When the main link
video is enabled, the scrambler/de-scrambler must be reset every 512th BS Symbol as
described in section 2.2.1.1 of the DisplayPort standard. For simulation purposes, force
a scrambler reset by writing a 1 to
0x0C0 before the
main link is enabled to reduce the amount of time after startup needed to align the
scrambler/de-scrambler.