Z90251 ZILOG [Zilog, Inc.], Z90251 Datasheet - Page 41

• Manufacturer Part Number: Z90251
• Description: eZVision 200 Television Controllers with OSD
• Manufacturer: ZILOG [Zilog, Inc.]

5.4
Table 17 BGR Mesh Colors
Bit 3,P20 for Halftone, selects mesh or halftone effect. If bit 3 is set to 1, P20
outputs halftone. If reset to 0,P20 is a normal I/O pin.
Bit 2, Software Field Number/Polarity of Halftone Output, has several possible
values. The value of this bit remains the same for the entire mesh window; it does
not change from row to row.
If bit 3 is set to 1 (halftone), bit 2 defines the polarity of halftone output. If bit 3 is
reset to 0 and bit 1 is set to 1, then bit 2 defines the field number (even or odd).
Bit 1, Software Mesh, defines whether hardware or software sets the current field
number. When the value equals 0, hardware defines field number. When the
value equals 1, software defines the field number.
Bit
conjunction with
Mesh Window Row equals
the value is changed when the current row is part of the mesh window, partial or
missing characters are likely to be displayed.
OSD Fade
Fading is the gradual disappearance of the OSD. Fading occurs vertically, up or
down. Figure 11 shows the fade-down effect.
Fade control registers can only be updated during V
Otherwise, unexpected results can occur.
B
0
0
0
0
1
1
1
1
0
, Mesh Enable, disables or enables using mesh. This field is used in
G
0
0
1
1
0
0
1
1
MR_EN (0)
R
0
1
0
1
0
1
0
1
0
. The value of Mesh Enable is changed only when
(the current OSD row is not part of a mesh window). If
Color
Black
Red
Green
Yellow
Blue
Magenta
Cyan
White
32 KB Television Controller with OSD
SYNC
, not during row interrupt.
PS001301-0800
33