Datasheet

Table Of Contents
Section 21 LCD Controller/Driver
Rev. 2.00 Jul. 04, 2007 Page 467 of 692
REJ09B0309-0200
(c) LCD Drive Power Supply Setting
With this LSI, 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.
(2) Software Settings
(a) Duty Selection
Any of four duty cycles—static, 1/2 duty, 1/3 duty, or 1/4 duty—can be selected with bits DTS1
and DTS0.
(b) Segment Driver Selection
The segment drivers to be used can be selected with bits SGS3 to SGS0.
(c) Frame Frequency Selection
The frame frequency can be selected by setting bits CKS3 to CKS0. The frame frequency should
be selected in accordance with the LCD panel specification. For the clock selection method in
watch mode, subactive mode, and subsleep mode, see section 21.4.4, Operation in Power-Down
Modes.
(d) A or B Waveform Selection
Either the A or B waveform can be selected as the LCD waveform to be used by means of
LCDAB.
(e) LCD Drive Power Supply Selection
When an external power supply circuit is used, turn the LCD drive power supply off with the PSW
bit.