Datasheet

Section 21 LCD Controller/Driver
Rev. 2.00 Jul. 04, 2007 Page 473 of 692
REJ09B0309-0200
Table 21.5 shows output levels.
Table 21.5 Output Levels
Data 0 0 1 1
M 0 1 0 1
Static Common output V1 VSS V1 VSS
Segment output V1 VSS VSS V1
1/2 duty Common output V2, V3 V2, V3 V1 VSS
Segment output V1 VSS VSS V1
1/3 duty Common output V3 V2 V1 VSS
Segment output V2 V3 VSS V1
1/4 duty Common output V3 V2 V1 VSS
Segment output V2 V3 VSS V1
M: LCD alternation signal
21.4.3 3-V Constant-Voltage Power Supply Circuit
This LSI incorporates a 3-V constant-voltage power supply circuit consisting of a band gap
reference circuit (BGR), a triple step-up circuit, etc. This allows the 3 V constant voltage to drive
LCD driver independently of Vcc.
Before activating a step-up circuit, operate the LCD controller/driver, and set the duty cycle, pin
function, display data, frame frequencies, etc. Insert a capacitance of 0.1 µF between the C1 pin
and C2 pin, and connect a capacitance of 0.1 µF to each of V1, V2, and V3 pins. (See figure 21.9.)
After this setting, setting the BGRSTPN bit in the BGR control register (BGRMR) to 1 activates
the band gap reference circuit, generating 1 V constant voltage (V
LCD3
) at the V3 pin. Furthermore,
selecting the step-up circuit clock of the LCD control register 2 (LCR2) and setting the SUPS bit
to 1 activates the triple step-up circuit, generating 2 V constant voltage, twice V
LCD3
, at the V2 pin,
and generating 3 V constant voltage, triple V
LCD3
, at the V1 pin.