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NUC970 Technical Reference Manual
Publication Release Date: Dec. 15, 2015
- 1108 -
Revision V1.30
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The Display Controller supports various video/OSD overlay control function. The OSD can be
turned on and overlaid with video data by setting register OSD_EN (DCCS[2]) and OSD window
coordinates registers, OSD_WINS and OSD_WINE. The OSD data format supports 8/16/24-bit
direct-color mode. The OSD format is selected by register OSD_SRC (DCCS[14:12]). The OSD
data can be transparent, blinking or mixed with video data by setting overlay control registers
OSD_OVERLAY. The display condition is depicted in the following table:
Window-Key
Color-Key
OCR1
OCR0
Display
0
X
X
X
Video
1
0
X
0
Video
1
0
X
1
OSD
1
0
X
2
Video+OSD
1
1
0
X
Video
1
1
1
X
OSD
1
1
2
X
Video+OSD
The Color-Key value indicates the color-key condition is matched or un-matched. The OSD color-
key pattern is defined in register OSD_CKEY for V/U/Y or B/G/R components according to the
source color format OSD_SRC (DCCS[14:12]). The color-key mask is also provided in registers
OSD_CMASK. Only the color-
key pattern, which with the mask bits has been set to “1”, will be
compared with the OSD graphic data.
Setting the value of register VA_SYNW (OSD_OVERLAY[6:4]) can change the weighting of
mixing the data of video and OSD streams. In addition, the OSD can be periodically blinking by
setting the blinking cycle time in register BLINK_VCNT (OSD_OVERLAY[23:16]).
Setting the value of registers OSK_SKIP1 and OSD_SKIP2 can separate the OSD window into 3
sub-windows. The OSD data fetching of lines enclosed by SKIP regions is skipped. So, the OSD
frame buffer size can be reduced. The display condition is depicted in the following diagram:
OSD 2
OSD_skip1_sy
OSD_skip1_ey
OSD_skip2_sy
OSD_skip2_ey
(OSD_win_sx,OSD_win_sy)
(OSD_win_ex,OSD_win_ey)
VA
OSD1
OSD 3
OSD 2
OSD_skip1_sy
OSD_skip1_ey
OSD_skip2_sy
OSD_skip2_ey
(OSD_win_sx,OSD_win_sy)
(OSD_win_ex,OSD_win_ey)
VA
OSD1
OSD 3