
S3C880A/F880A
ON-SCREEN DISPLAY
13-31
OSD SPACE COLOR CONTROL REGISTER (OSDCOL)
RGB output selection
S3C880A has two RGB output mode: digital mode and analog mode.
In Digital mode, OSDCOL.0 must be set to 0. RGB output has two levels, VSS and VDD. Eight colors can be
produced: black, blue, green, cyan, red, magenta, yellow and white. OSD palette color control registers,
OSDPLTR1, OSDPLTR2, OSDPLTG1, OSDPLTG2, OSDPLTB1, and OSDPLTB2, are not used in this mode.
In analog mode, OSDCOL.0 must be set to 1. R.G.B output color bright can be selected among four levels
respectively. 64 colors can be selected by setting OSD palette color control registers, OSDPLTR1, OSDPLTR2,
OSDPLTG1, OSDPLTG2, OSDPLTB1, and OSDPLTB2. In one display row you can select 8 colors, color mode
0–7, by setting COLBUF.2–.0. The color selected by color mode 0–7 can be changed in every display row.
Inter-row space halftone
Inter-row spacing is the distance (in H-sync pulses) between two rows of displayed characters and can be
changed by setting ROWCON.2-.0. Also halftone character can be changed for this inter-row spacing.
For OSDCOL.1=0, halftone function of inter-row space region is the same as that of the character background
region. That is, if the halftone function of character background region is enabled by setting HTCON.3 to “1”, the
halftone function of inter-row space region is enabled. When HTCON.3 is set to “1”, halftone function of
character background is enabled regardless of the value of HTCON.2.
For OSDCOL=1 (depend on frame background halftone), inter-row space halftone function is enabled when the
value of HTCON.3 and HTCON.2 are set to "1".
Inter-row space color
Inter-row space color depends on the character background color and frame background color by COLCON.
When OSDCOL.2 is “0”, inter-row space color depends on the current character background color; when
OSDCOL.2 is “1”, inter-row space color depends on the current frame background color.
Fringe dot size selection
1 dot (when OSDCOL.3 is “0”) is a fringe size, which is set by OSDFRG1 and OSDFRG2.
For 1/2 dot fringe size (when OSDCOL.3 is “1”), fringe function is set by 1/2 dot unit. In the interlaced scan, even
field line and odd field line are added to form 1 dot of length. If character size of length is x1 or x3 in the 1/2 dot
fringe size, blinking can occur. So, 1 dot fringe size method is recommended.
Inter character smoothing control
If inter character smoothing is enabled (when OSDCOL.4 is “1”), adjacent character is considered as one
character and smoothing function is enabled.