HD66781 Datasheet, PDF (103/196 Pages) Renesas Technology Corp – 720-channel Source Driver for a-Si TFT/Low Temperature Poly-Si TFT Panels with 262,144-color display RAM

HD66781
Preliminary
OSD and α blending processing
The following is an example of display with OSD and α blending functions with the HD66781. In the
following example, the unused RAM area, which is not used for base image display, is used for OSD and α
blending RAM area.
HD66781 RAM data
First panel
base i mage ar ea
H D66781 first panel
di spla y
100%OSD di spl ay icon
Fir st OSD image ar ea
Second OSD i mage ar ea
Thir d OSD i mage ar ea
50%OSD display (Base color: yellow)
100% OSD display (letters)
100 % OSD di spl ay(icon)
Display with OSD and α blending
OSD image data format
OSD image data format (α bit arrangement) is changeable with ODF bits. Select an appropriate format for
the system to process. When writing an OSD image to RAM, set OSD to 1 beforehand. Specify the RAM
write area by the window address.
OSD image data format
ODF
0
1
Normal
data
D
17
D
16
D
15
D
14
D
13
D
12
D
11
D
10
D9 D8
D7 D6 D5 D4 D3 D2
D1 D0
R5 R4 R3 R2 R1
2 G5 G4 G3 G2 G1
1 B5 B4 B3 B2 B1
0
2
1
0 R4 R3 R2 R1 R0 G4 G3 G2 G1 G0 B4 B3 B2 B1 B0
R5 R4 R3 R2 R1 R0 G5 G4 G3 G2 G1 G0 B5 B4 B3 B2 B1 B0
OSD image display setting
To make a setting for OSD image display,
1. Specify OSD RAM area (OSA, OEA)
2. Specify OSD position
3. Set OSD ENABLE (OSDE)
Rev.0.5, July.31.2003, page 103 of 196