2 POWER SUPPLY, RESET, AND CLOCKS
S1C31D50/D51 TECHNICAL MANUAL
Seiko Epson Corporation
2-1
(Rev. 2.00)
2 Power Supply, Reset, and Clocks
The power supply, reset, and clocks in this IC are managed by the embedded power generator, system reset control-
ler, and clock generator, respectively.
2.1 Power Generator (PWGA)
2.1.1 Overview
PWGA is the power generator that controls the internal power supply system to drive this IC with stability and low
power. The main features of PWGA are outlined below.
• Embedded V
D1
regulator
- The V
D1
regulator generates the V
D1
voltage to drive internal circuits, this makes it possible to keep current
consumption constant independent of the V
DD
voltage level.
- The V
D1
regulator supports two operation modes, normal mode and economy mode, and setting the V
D1
regu-
lator into economy mode at light loads helps achieve low-power operations.
- The V
D1
regulator supports two voltage modes, mode0 and mode1, and setting the V
D1
regulator into mode1
during low-speed operation helps achieve low-power operations.
Figure 2.1.1.1 shows the PWGA configuration.
C
VDDQSPI
PWGA
Internal circuits
V
D1
regulator
V
DD
V
DD
or
another external
power supply
V
D1
V
D1
V
SS
REGMODE[1:0]
REGSEL
REGDIS
C
PW1
C
PW2
+
I/O ports
(except for P9 port groups)
Quad synchronous serial
interface and I/O ports
(P9 port group)
V
DDQSPI
Figure 2.1.1.1 PWGA Configuration
2.1.2 Pins
Table 2.1.2.1 lists the PWGA pins.
Table 2.1.2.1 List of PWGA Pins
Pin name
I/O
Initial status
Function
V
DD
P
–
Power supply (+)
V
SS
P
–
GND
V
D1
A
–
V
D1
regulator output pin
V
DDQSPI
P
–
QSPI interface (QSPI-Flash) and I/O power supply (for P9 port group)
For the V
DD
/V
DDQSPI
operating voltage ranges and recommended external parts, refer to “Recommended Operating
Conditions, Power supply voltage V
DD
/V
DDQSPI
” in the “Electrical Characteristics” chapter and the “Basic External
Connection Diagram” chapter, respectively.
V
DDQSPI
V
DDQSPI
is the power supply dedicated for the quad synchronous serial interface (QSPI-Flash). It is also used as
the power supply for the I/O ports P90 to P95.