SIC63616-(Rev. 1.0) NO. P34
3240-0412
Table 4.2.2.1 lists settings of the above registers according to the supply voltage V
DD
.
Table 4.2.2.1 Power control register settings according to supply voltage V
DD
Power supply
voltage V
DD
1.6 to 2.5 V
2.5 to 5.5 V
DBON
1
0
HLON
0
0
VDSEL
0
0
VCSEL
1
0
Power source for internal and
oscillation system voltage regulators
V
DD
V
DD
Power source for LCD system
voltage regulator (V
C2
reference)
V
D2
(
≈
V
DD
×
2)
V
DD
When V
C2
reference LCD drive power option is selected
Power supply
voltage V
DD
1.6 to 5.5 V
DBON
0
HLON
0
VDSEL
0
VCSEL
0
Power source for internal and
oscillation system voltage regulators
V
DD
Power source for LCD system
voltage regulator (V
C1
reference)
V
DD
When V
C1
reference LCD drive power option is selected
4.2.3 Heavy load protection function
In order to ensure a stable circuit behavior and LCD display quality even if the power supply voltage
fluctuates due to driving an external load, the internal operating voltage regulator and the LCD system
voltage regulator have a heavy load protection function.
The internal operating voltage regulator enters heavy load protection mode by writing "1" to the
VDHLMOD register and it ensures stable V
D1
output. Use the heavy load protection function when a heavy
load such as a lamp or buzzer is driven with a port output.
The LCD system voltage regulator enters heavy load protection mode by writing "1" to the VCHLMOD
register and it ensures stable V
C1
–V
C5
outputs. Use the heavy load protection function when the LCD
display has inconsistencies in density.
Note: Current consumption increases in heavy load protection mode, therefore do not set heavy load
protection mode with software if unnecessary.
4.2.4 I/O memory for power control
Table 4.2.4.1 shows the I/O address and the control bits for power control.
Table 4.2.4.1 Power control bits
Address
Comment
D3
D2
Register
D1
D0
Name Init
∗
1
1
0
FF03H
VCHLMOD VDHLMOD General LPWR
R/W
VCHLMOD
VDHLMOD
General
LPWR
0
0
0
0
On
On
1
On
Off
Off
0
Off
Heavy load protection mode On/Off for LCD system voltage regulator
Heavy load protection mode On/Off for internal voltage regulator
General-purpose register
LCD system voltage regulator On/Off
FF02H
VDSEL VCSEL HLON
DBON
R/W
VDSEL
VCSEL
HLON
DBON
0
0
0
0
1
V
D2
On
On
0
V
DD
Off
Off
General-purpose register
Power source select for LCD system voltage regulator
Power voltage booster/halver halving mode On/Off
Power voltage booster/halver boost mode On/Off
*1 Initial value at initial reset
*3 Constantly "0" when being read
*2 Not set in the circuit
DBON: Power supply voltage booster/halver boost mode On/Off register (FF02H•D0)
Activates the power supply voltage booster/halver in boost mode.
When "1" is written: Booster On
When "0" is written: Booster Off
Reading: Valid
When "1" is written to DBON, the power supply voltage booster/halver activates in boost mode and almost
doubles the V
DD
voltage to generate the V
D2
voltage. Turn the power supply voltage booster/halver on
when driving the LCD system voltage regulator with V
D2
(V
C2
reference voltage, V
DD
= 1.6 to 2.5 V). When
"0" is written to DBON, the voltage boost operation is deactivated. Be sure to set DBON to "0" (Off) when
driving the LCD system voltage regulator with V
DD
. Furthermore, do not set both DBON and HLON to "1".
At initial reset, this register is set to "0".
Содержание S1C63616
Страница 1: ...S1C63616 Technical Manual Rev 1 0 ...