h8s-2646 Renesas Electronics Corporation., h8s-2646 Datasheet - Page 681

• Manufacturer Part Number: h8s-2646
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2600 Series
• Manufacturer: Renesas Electronics Corporation.

18.3
18.3.1
To perform LCD display, the hardware and software related items described below must first be
determined.
Hardware Settings
• Using 1/2 duty
• Panel display
• LCD drive power supply setting
When 1/2 duty is used, interconnect pins V2 and V3 as shown in figure 18.2.
As the impedance of the built-in power supply split-resistance is large, the display may lack
sharpness when driving a panel. In this case, refer to section 18.3.4, Boosting the LCD Drive
Power Supply. When static or 1/2 duty is selected, the common output drive capability can be
increased. Set CMX to 1 when selecting the duty cycle. In this mode, with a static duty cycle
pins COM4 to COM1 output the same waveform, and with 1/2 duty the COM1 waveform is
output from pins COM2 and COM1, and the COM2 waveform is output from pins COM4 and
COM3.
With the H8S/2646 Group, there are two ways of providing LCD power: by using the on-chip
power supply circuit, or by using an external power supply circuit.
When an external power supply circuit is used for the LCD drive power supply, connect the
external power supply to the V1 pin.
Operation
Settings up to LCD Display
Figure 18.2 Handling of LCD Drive Power Supply when Using 1/2 Duty
LPV
V
SS
CC
V1
V2
V3
Rev. 5.00 Sep 22, 2005 page 655 of 1136
Section 18 LCD Controller/Driver
REJ09B0257-0500