Visible to Intel only — GUID: cfs1656341754705
Ixiasoft
Visible to Intel only — GUID: cfs1656341754705
Ixiasoft
4.2. Full-Raster Start of Frame
For most standardized video resolutions the leading edge of the VSYNC pulse coincides with the true start of the frame boundary where video geometry counters are in coordinates (1,1). One exception is where the leading edge of VSYNC is usually offset by a certain amount of video lines, causing the VSYNC to misalign with the actual true start of frame. For instance, 720x240p60 VSYNC pulse is offset by 3 video lines, while 2880x480p60 is offset by 7 video lines. The position of the leading edge of VSYNC relative to the true start of frame location is defined in the relevant standards, such as SMPTE, VESA, and CEA. The full-raster protocol states you assert TUSER[0] at video coordinates (1,1), irrespective of where the actual leading edge of VSYNC occurs.