HD66781 Datasheet, PDF (39/196 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
HWM: When HWM =1, data are written to GRAM in high speed with low power consumption. In power
saving high-speed write mode, the data in the horizontal line of rectangular area specified by the window
address are stored in the line buffer and one-line data are written to GRAM at once. This minimizes the
number of RAM access required to write data and thereby reduces power consumption.
When HWM =1, the data write in horizontal direction must be executed by line of the specified window-
address range. If data write is terminated in the middle of the line, data in that line are not correctly written
to GRAM.
Note 1) Insertion of dummy write is not required in high-speed write mode.
Note 2) Data in the buffer will be erased if RAM write is terminated in the middle of a line and other instruction set is
executed.
Note 3) In the high-speed write mode, wait at least 2 write cycles (tcycw) of the normal write mode after RAM write before
making a transition from RAM write to index write.
BGR: Change the order of (R), (G), (B) dots to (B), (G), (R) when the dots are assigned to the 18-bit write
data.
BGR=0, the dot order (R), (G), (B) is not changed when 18-bit data are written to GRAM.
BGR =1, the dot order changes from (R), (G), (B) to (B), (G), (R) when 18-bit data are written to
GRAM. The assignment of α bit of OSD data is also changed.
DFM: Set the data format for 3-RAM-write 18-bit data transfers in 80-system 8-bit interface (big-endian)
mode when IM3-0 = GND/GND/ Vcc1/Vcc1 in conjunction with TRI.
DFM =0, RGB 18-bit data are written to GRAM by byte-boundary 3 transfers.
DFM =1, RGB 18-bit data are written to GRAM by 3 x 6-bit transfer.
Set the data format for 2-RAM-write 18-bit data transfers in 80-system 16-bit interface mode when IM3-0
= GND/GND/Vcc1/GND in conjunction with TRI.
DFM =0, RGB 18-bit data are written to GRAM in the MSB format by 2 transfers.
DFM =1, RGB 18-bit data are written to GRAM in the LSB format by 2 transfers.
DFM must be set to 0, when not using 8- or16-bit interface.
TRI: Make the 3-RAM-write transfers available in 80-system 8-bit interface (big-endian) when IM3-0 =
GND/GND/Vcc1/Vcc1.
TRI =0, 16-bit RAM data are transferred in 2 transfers.
TRI =1, 18-bit RAM data are transferred in 3 transfers.
Make the 2-RAM-write transfers available in 80-system 16-bit interface (big-endian) when IM3-0 =
GND/GND/Vcc1/GND.
TRI =0, 16-bit RAM data are transferred in one transfer.
TRI =1, 18-bit RAM data are transferred in 2 transfers.
TRI must be set to 0, when not using 8- or 16-bit interface. During RAM read, set TRI = 0.
Rev.0.5, July.31.2003, page 39 of 196