ST92196A STMicroelectronics, ST92196A Datasheet - Page 136

• Manufacturer Part Number: ST92196A
• Description: 8/16-bit Mcu For Tv Applications With Up To 96k Rom, On-screen-display And 1 Or 2 Data Slicers
• Manufacturer: STMicroelectronics

OSD CONTROLLER (Cont’d)
8.5.6.4 Background Palettes
The background palettes (Basic and Extended)
both use the same principle:
The basic background palette is stored in OS-
DRAM (segment 22h) starting from 30h to 4Fh
(see
The extended background palette is stored in OS-
DRAM (segment 22h) starting from 70h to 8Fh
(see
A 16-bit word is used to define each color in the
palette, located at even addresses between 30h
and 4Eh (even value) for the basic background
palette, and between 70h and 8Eh (even value) for
the extended background one.
Figure 63. Basic Background Palette Mapping
Bit 15 = M Background color change bit .
This bit determines where the background color
change occurs.
0: The background color change takes effect im-
1: The background color change occurs in the
Notes:
– When the preceding character is slanted (italics
– If the M bit is used in parallel mode at the begin-
on, only available in serial mode), a background
color change only occurs in the center of the
character regardless of the M bit value.
ning of a row, it is strongly recommended to in-
sert a space or null character before setting the
M bit in order to control the first half background
color.
15
M
mediately.
center of the character.
Figure
Figure
4Fh
30h
32h
34h
59).
59).
BR[1:0] BG[2:0] BB[2:0]
BR[1:0] BG[2:0] BB[2:0]
BR[1:0] BG[2:0] BB[2:0]
M BT[2:0] BR2
M BT[2:0] BR2
M BT[2:0] BR2
BT2
BT1
BT0
Color
Color
Color
15
BR2
0
1
8
- ON SCREEN DISPLAY CONTROLLER (OSD)
BR1
7
Bits 14:12 = free for the user
Bits 11:9 = BT[2:0] Background Translucency
These bits configure the background translucency
level applied to the color (refer to
for more details).
BT[2:0] = 7 means that this color will be fully
opaque (no video mixed in it on the display)
BT[2:0] = 0 means that this color will be fully trans-
parent (the video is displayed instead of this color)
Bits 8:6 = BR[2:0] Background Red color
These bits configure the background red intensity
for the color.
BR[2:0] = 0 means that no red is used to define the
color.
BR[2:0] = 7 means that the maximum red intensity
is used in the color.
Bits 5:3 = BG[2:0] Background Green color
These bits configure the background green inten-
sity for the color.
BG[2:0] = 0 means that no green is used to define
the color.
BG[2:0] = 7 means that the maximum green inten-
sity is used in the color.
Bits 2:0 = BB[2:0] Background Blue color
These bits configure the background blue intensity
for the color.
BB[2:0] = 0 means that no blue is used to define
the color.
BB[2:0] = 7 means that the maximum blue intensi-
ty is used in the color.
BR0
BG2
BG1
BG0
BB2
Section 8.5.3.11
BB1
BB0
0
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