
S1C6P366 TECHNICAL MANUAL
EPSON
7
CHAPTER 2: POWER SUPPLY AND INITIAL RESET
2.1.1 Voltage <VD1> for oscillation circuit and internal circuits
VD1 is the operating voltage for the oscillation circuit, and is generated by the oscillation system voltage
regulator for stabilizing oscillation.
In the S1C63358/63158, it is necessary to switch the VD1 voltage level according to the oscillation circuit
and operating frequency by controlling the voltage regulator. In the S1C6P366, the VD1 voltage level is
fixed, so software control for switching the VD1 level does not affect the actual output voltage. However,
when using the S1C6P366 as a development tool for the S1C63358/63158, the VD1 software control
sequence must be implemented according to the model.
Refer to Chapter 6, "Differences from Mask ROM Models", for details.
2.1.2 Voltage <VC1–VC3> for LCD driving
VC1 to VC3 are the voltages for LCD drive, and are generated by the LCD system voltage circuit to
stabilize the display quality.
Since the minimum operating voltage of the S1C6P366 is 2.7 V, the LCD system voltage circuit generates
VC2 as the reference voltage, and generates two other voltages by boosting or reducing VC2 (VC1 = 1/
2VC2, VC3 = 3/2VC2).
Refer to Chapter 9, "Electrical Characteristics", for voltage values of VC1 to VC3.
2.1.3 Operating mode of power supply circuit
The oscillation system voltage regulator and A/D converter power supply circuit operate in normal
mode that uses VDD as the power source.
In the S1C63358/63158, a booster mode (VC2 mode) is provided in order to guarantee low-voltage
operation, therefore it is necessary to switch the operating mode. Since the power supply voltage of the
S1C6P366 is 2.7 V or more, this switching is not necessary and the software control does not affect the
operating mode. However, when using the S1C6P366 as a development tool for the S1C63358/63158, the
operating mode control routine must be implemented according to the model.
Refer to Chapter 6, "Differences from Mask ROM Models", for details.