Lucent Technologies MN10285K - Manual (Page 174)

On-Screen Display
ROM
MN102H75K/F75K/85K/F85K LSI User Manual Panasonic Semiconductor Development Company
173
Panasonic
7.9.2 Graphics ROM Organization in Different Color Modes
The graphics layer supports up to sixteen colors, in the 16-color mode, but also
supports 2-, 4-, and 8-color modes. The smaller the number of colors, the less
ROM area required per tile. The figures in this section illustrate the ROM organi-
zation for each color mode.
The example in figure 7-10 demonstrates the graphics ROM setup for line 16 of
the code 00 data when the graphics layer is in 16-color mode. The four bits of
data for each pixel, in sheets 1, 2, 3, and 4, determine the color palette used for
that pixel.
Figure 7-10 Graphics ROM Setup Example for a Single Line
Line 1 data
Line 2 data
Line 3 data
.
.
.
Line 15 data
Line 16 data 8 bytes
GROMEND − 7
GROMEND − 6
GROMEND − 5
GROMEND − 4
GROMEND − 3
GROMEND − 2
GROMEND − 1
GROMEND
Sheet 1 bits 7 to 0
Sheet 1 bits 15 to 8
Sheet 2 bits 7 to 0
Sheet 2 bits 15 to 8
Sheet 3 bits 7 to 0
Sheet 3 bits 15 to 8
Sheet 4 bits 7 to 0
Sheet 4 bits 15 to 8 1 byte
Graphics tile
Sheet 4
Sheet 3
Sheet 2
1 dot = 4 bits
= 16 colors
Bit 15 Bit 0
16 bits
Line 16
Line 1
Line 2
Line 3
(16-color mode)
(16-color mode)
0000 0000
0000 0000
0000 0000
0000 0000
1010 1010
1100 1100
1111 0000
0000 0000
(Setup example)
Use graphics palette 0
Use graphics palette 1
Use graphics palette 2
Use graphics palette 3
Use graphics palette 4
Use graphics palette 5
Use graphics palette 6
Use graphics palette 7
Bit 0 Bit 15
Graphics tile
Line 1
Line 2
Line 3
Line 16
In this example, line 16 of the code 00
graphics tile is set in 16-color mode.
Sheet 1