HD66781 Datasheet, PDF (134/196 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
VSYNC Interface
The HD66781 incorporates a VSYNC-I/F, which enables moving picture display with a system interface
and the frame synchronization signal (VSYNC) only. This interface enables the display of moving pictures
with minimum modification to the conventional system.
LCDC/MPU
VSYNC
CS*
RS ^HD66781
WR*
DB17-10,8-1
16
VSYNC interface
The VSYNC-I/F is selected by setting DM1-0 = 10 and RM = 0. In the VSYNC I/F mode, the internal
display operations are synchronized with VSYNC. By writing data to RAM through the system interface in
a speed that is higher for more than a fixed speed than the internal display operation speed, it enables
moving picture display through a system interface and flicker-free screen update.
Display operations are executed by the internal clock generated by the internal oscillator and the VSYNC
input. All display data are stored in RAM. Therefore, it only requires transfer of the data that is written
over to update the screen, thereby minimizing the numbers of data transfers while displaying moving
picture. The use of high-speed write mode (HWM = 1) with VSYNC interface enables RAM access in
high speed with low power consumption.
VSYNC
System interface
RAM data
Write
Display
execution with
internal clock
Moving picture data transmission through VSYNC interface
Note 1) Data must be written to RAM in the high-speed write mode (HWM = 1) in VSYNC interface mode.
Rev.0.5, July.31.2003, page 134 of 196