VII LCD CONTROLLER BLOCK: LCD CONTROLLER

(4)8-bpp (256-color) mode

One pixel is represented by 8 bits, displayed in 256 colors. This mode is not available for grayscale display. In this mode, 256 discrete combinations are configured using eight entries in each of the red and green look- up tables, and four entries in the blue look-up table. Bits 5–7 in one byte of pixel data are used as an index to the red look-up table, while bits 2–4 and bits 0–1 are used as indices to the green and blue look-up tables, respectively.

(bit 7)

Pixel data

(bit 0)

R2 R1 R0 G2 G1 G0 B1 B0

A-1

3-bit

Rpixel data

3-bit G pixel data

 

 

 

Index

Red look-up table

"000"

 

 

0

4-bit R data for R pixel data "000"

 

 

"001"

 

 

1

4-bit R data for R pixel data "001"

 

 

"010"

 

 

2

4-bit R data for R pixel data "010"

 

 

"011"

 

 

3

4-bit R data for R pixel data "011"

 

 

"100"

 

 

4

4-bit R data for R pixel data "100"

 

 

"101"

 

 

5

4-bit R data for R pixel data "101"

 

 

"110"

 

 

6

4-bit R data for R pixel data "110"

 

 

"111"

 

 

7

4-bit R data for R pixel data "111"

 

 

 

 

 

Index

Green look-up table

"000"

 

 

0

4-bit G data for G pixel data "000"

 

 

"001"

 

 

1

4-bit G data for G pixel data "001"

 

 

"010"

 

 

2

4-bit G data for G pixel data "010"

 

 

"011"

 

 

3

4-bit G data for G pixel data "011"

 

 

"100"

 

 

4

4-bit G data for G pixel data "100"

 

 

"101"

 

 

5

4-bit G data for G pixel data "101"

 

 

"110"

 

 

6

4-bit G data for G pixel data "110"

 

 

"111"

 

 

7

4-bit G data for G pixel data "111"

 

 

 

 

 

 

 

 

Index

Blue look-up table

2-bit

"00"

 

 

0

4-bit B data for B pixel data "00"

 

 

"01"

 

 

1

4-bit B data for B pixel data "01"

B pixel

 

 

 

 

"10"

 

 

2

4-bit B data for B pixel data "10"

data

 

 

 

"11"

 

 

3

4-bit B data for B pixel data "11"

 

 

 

 

Figure 2.15 Look-up Table in 8-bpp (256-Color) Mode

4-bit R display data

4-bit G display data

4-bit B display data

Table 2.12 shows an example of the basic data setting, using the display colors shown in Table 2.13.

Table 2.12 Example of Look-up-Table Settings in 8-bpp (256-Color) Mode

Index

R look-up table

G look-up table

B look-up table

0

0

0

0

1

3

3

5

2

5

5

0xA

3

7

7

0xF

4

9

9

0

5

0xB

0xB

0

6

0xD

0xD

0

7

0xF

0xF

0

8–15

0

0

0

Table 2.13 Display Colors in the Above Setup Example

Pixel data

Color

000 000 00

Black

000 000 10

Dark blue

000 100 00

Dark green

000 100 10

Dark cyan

100 000 00

Dark red

100 000 10

Dark magenta

100 100 00

Dark yellow

100 100 10

Gray

Pixel data

Color

000 000 00

Black

000 000 11

Bright blue

000 111 00

Bright green

000 111 11

Bright cyan

111 000 00

Bright red

111 000 11

Bright magenta

111 111 00

Bright yellow

111 111 11

White

B-VII

LCDC

S1C33L03 FUNCTION PART

EPSON

B-VII-2-17