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S3C2440A RISC MICROPROCESSOR LCD CONTROLLER
15-21
256 PALETTE USAGE (TFT)
Palette Configuration and Format Control
The S3C2440A provides 256 color palette for TFT LCD Control.
The user can select 256 colors from the 64K colors in these two formats.
The 256 color palette consists of the 256 (depth) x 16-bit SPSRAM. The palette supports 5:6:5 (R:G:B) format and
5:5:5:1(R:G:B:I) format.
When the user uses 5:5:5:1 format, the intensity data(I) is used as a common LSB bit of each RGB data. So,
5:5:5:1 format is the same as R(5+I):G(5+I):B(5+I) format.
In 5:5:5:1 format, for example, the user can write the palette as in Table 15-5 and then connect VD pin to TFT LCD
panel(R(5+I)=VD[23:19]+VD[18], VD[10] or VD[2], G(5+I)=VD[15:11]+ VD[18], VD[10] or VD[2], B(5+I)=VD[7:3]+
VD[18], VD[10] or VD[2].), and set FRM565 of LCDCON5 register to 0.
Table 15-4. 5:6:5 Format
INDEX\Bit Pos. 15 1413 12 11 1098765432 1 0 Address
00H R4 R3 R2 R1 R0 G5 G4 G3 G2 G1 G0 B4 B3 B2 B1 B0
1)
0X4D000400
01H R4 R3 R2 R1 R0 G5 G4 G3 G2 G1 G0 B4 B3 B2 B1 B0 0X4D000404
....... .......
FFH R4 R3 R2 R1 R0 G5 G4 G3 G2 G1 G0 B4 B3 B2 B1 B0 0X4D0007FC
Number of VD
23 22 21 20 19 15 14 13 12 11 10 7 6 5 4 3
Table 15-5. 5:5:5:1 Format
INDEX\Bit Pos. 15 1413 12 11 1098765432 1 0 Address
00H R4 R3 R2 R1 R0 G4 G3 G2 G1 G0 B4 B3 B2 B1 B0 I 0X4D000400
01H R4 R3 R2 R1 R0 G4 G3 G2 G1 G0 B4 B3 B2 B1 B0 I 0X4D000404
....... .......
FFH R4 R3 R2 R1 R0 G4 G3 G2 G1 G0 B4 B3 B2 B1 B0 I 0X4D0007FC
Number of VD
23 2221 20 19 15141312117654 3
2)
Notes
1. 0x4D000400 is Palette start address.
2. VD18, VD10 and VD2 have the same output value, I.
3. DATA[31:16] is invalid.
Palette Read/Write
When the user performs Read/Write operation on the palette, HSTATUS and VSTATUS of LCDCON5 register
must be checked, for Read/Write operation is prohibited during the ACTIVE status of HSTATUS and VSTATUS.
Temporary Palette Configuration
The S3C2440A allows the user to fill a frame with one color without complex modification to fill the one color to the
frame buffer or palette. The one colored frame can be displayed by the writing a value of the color which is
displayed on LCD panel to TPALVAL of TPAL register and enable TPALEN.