VII LCD CONTROLLER BLOCK: LCD CONTROLLER
B-VII-2-14 EPSON S1C33L03 FUNCTION PART
Color-mode look-up tables
In color mode, the LCD controller uses the red (R), green (G), and blue (B) look-up tables. Each color
element is represented by 4-bit data. RGB = 000 is black, RGB = F00 is red, RGB = 080 is 50% luminance
green, RGB = F0F is magenta, RGB = FFF is white, and so on. In this way, colors are determined by the
proportions of the three color elements. If the luminance of each color element is represented by 4 bits, then
we obtain 16 × 16 × 16 = 4,096 colors. Of these, select as many pieces of color data as can be used for the
available display mode (2, 4, 16, or 256 colors), and write them to the valid entries of the look-up tables
before using the LCD panel.
In personal-computer applications, the luminance of each color element is generally represented by 8 bits
(0x00 to 0xFF). To set up the LCD panel by referring to those colors, write the 4 high-order bits of that data
to the look-up tables.
The differences in configurations between display modes are shown below.
(1) 1-bpp (2-color) mode
Use the first two entries of each look-up table. Select 2-color data from among the 4,096 colors, and write it
to the respective entries. The RGB data in entry 0 is output for pixel data "0", and the RGB data in entry 1 is
output for pixel data "1". For monochrome display, write 0x0 to entry 0 and 0xF to entry 1 in each of the red,
green, and blue look-up tables before using the LCD panel.
4-bit R display data
Red look-up tableIndex
Unused
0
1
2
:
15
4-bit R data for pixel data "0"
4-bit R data for pixel data "1"
4-bit G display data
Green look-up tableIndex
Unused
0
1
2
:
15
4-bit G data for pixel data "0"
4-bit G data for pixel data "1"
4-bit B display data
Blue look-up tableIndex
Unused
0
1
2
:
15
4-bit B data for pixel data "0"
4-bit B data for pixel data "1"
1-bit pixel data
"0"
"1"
Figure 2.12 Look-up Table in 1-bpp (2-Color) Mode
Table 2.9 shows an example of the basic data setting.
Table 2.9 Example of Look-up-Table Settings in 1-bpp (2-Color) Mode
Index R look-up table G look-up table B look-up table
0000
10xF0xF0xF
2–15 0 0 0