HD66760 Datasheet, PDF (21/105 Pages) Hitachi Semiconductor – 104 X 80-dot Graphics LCD Controller/Driver for 256 Colors

HD66760
LCD-Driving-Waveform Control (R02h)
RST: When RST = 1, software function is started. This function is same as hardware RESET* pin. It takes 10
clock cycle period. The RST will be automatically cleared. Therefore, after 10 clock cycle other instruction
can be issued. Do not set the RST during stand-by mode.
B/C: When B/C = 0, a B-pattern waveform is generated and alternates in every frame for LCD drive. When
B/C = 1, a C-pattern waveform is generated and alternates in each raster-row specified by bits EOR and
NW4-NW0 in the LCD-driving-waveform control register. For details, see the n-raster-row Reversed AC
Drive section.
EOR: When the C-pattern waveform is set (B/C = 1) and EOR = 1, the odd/even frame-select signals and the
n-raster-row reversed signals are EORed for alternating drive. EOR is used when the LCD is not alternated
by combining the set values of the LCD drive duty ratio and the n raster-row. For details, see the n-raster-row
Reversed AC Drive section.
NW4–0: Specify the number of raster-rows n that will alternate at the C-pattern waveform setting (B/C = 1).
NW4-NW0 alternate for every set value + 1 raster-row, and the first to the 32nd raster-rows can be selected.
R/W RS DB15 DB14 DB13 DB12 DB11 DB10 DB9 DB8 DB7 DB6 DB5 DB4 DB3 DB2 DB1 DB0
W 1 0 0 0 0 0 0 0 RST 0 B/C EOR NW4 NW3 NW2 NW1 NW0
Figure 5 LCD-Driving-Waveform Control Instruction
Power Control (R03h)
BS2–0: The LCD drive bias value is set within the range of a 1/4 to 1/10 bias. The LCD drive bias value can
be selected according to its drive duty ratio and voltage. For details, see the Liquid-crystal-display Drive-bias
Selector section.
BT1–0: The output factor of VLOUT between three-times, four-times, five-times, and six-times step-up is
switched. The LCD drive voltage level can be selected according to its drive duty ratio and bias. Lower
amplification of the step-up circuit consumes less current.
PS1–0: The internal or external power supply is selected as the reference power supply for the LCD drive-
voltage generator.
DC1–0: The operating frequency in the step-up circuit is selected. When the step-up operating frequency is
high, the driving ability of the step-up circuit and the display quality become high, but the current
consumption is increased. Adjust the frequency considering the display quality and the current consumption.
AP1–0: The amount of fixed current from the fixed current source in the operational amplifier for V pins (V1
to V5) is adjusted. When the amount of fixed current is large, the LCD driving ability and the display quality
become high, but the current consumption is increased. Adjust the fixed current considering the display
quality and the current consumption.