HD66789 Datasheet, PDF (47/156 Pages) Renesas Technology Corp – 528-channel, One-chip Driver for Amorphous TFT Panels with 262,144-color display RAM, Power Supply Circuit, and Gate Circuit

HD66789
Preliminary
RGB interface mode (2)
When RGB-I/F is selected, RAM data are changeable through the system interface. This write operation
must be performed while display data are not being transmitted through the RGB-I/F (ENABLE = High).
When reverting from the system interface mode to the data transmission through the RGB interface, make a
new setting for the address set and index (R22h) after changing the aforementioned settings.
VSYNC interface mode
The internal display operation is synchronized with the frame-synchronizing signal (VSYNC) in the
VSYNC interface mode. By writing data to RAM at a fixed speed on the falling edge of VSYNC, it
enables moving pictures display with a system interface. In this case, there are some constraints in the
RAM write speed and methods. For details, see the “External Display Interface” section.
In the VSYNC-I/F mode, only VSYNC input is valid. Other input signals for the external display interface
are invalid.
The front porch (FP), back porch (BP) periods and display period (NL) are automatically generated in
accordance to the frame synchronizing signal (VSYNC) according to the register setting of HD66789.
Rev.0.12, May 09 2003, page 47 of 156