HD66781 Datasheet, PDF (137/196 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
Notes to the VSYNC interface
1. The aforementioned example of calculation is just a result of calculation. In the actual settings, causes
for the fluctuations such as internal oscillators and so on should be taken into consideration. It is
necessary to make a setting for RAM write speed with enough margins.
2. The aforementioned example of calculation is the value in case of writing over the entire screen.
Limiting the area for the moving picture display will create more margins for the RAM write speed.
RAM
write
Back porch (14 lines)
㩿㪉㪇㩷㫃㫀㫅㪼㫊㪀
Display
operation
Panel
Moving picture
Display
(280 lines)
[lines]
320
300
RAM write
5.70MHz
R-C oscillation
㫧10%
FP=2H
Display
operation
㩿㪉㪇㩷㫃㫀㫅㪼㫊㪀
Front porch (2 lines)
Blank period
20
0
BP=14H
VSYNC
11.8
13.4
[ms]
16.67
(60Hz)
Condition on using VSYNC interface
3. A front porch period continues after the completion of 1 frame display and until the next input of
VSYNC.
4. The transition between the internal clock operation mode (DM1-0 = 00) and the VSYNC interface
mode becomes effective after displaying one frame made during instruction setting.
5. In the VSYNC interface mode, the partial display, vertical scroll, and interlaced drive functions are not
available.
6. In the VSYNC interface mode, set AM to 0 to transmit display data in the aforementioned method.
7. In the VSYNC interface mode, write display data to RAM in the high speed write mode (HWM = 1)
Rev.0.5, July.31.2003, page 137 of 196