aPPenDiX B POWeR SaVinG
aP-B-2
Seiko epson Corporation
S1C17624/604/622/602/621 TeChniCal Manual
• Supply voltage detector (SVD)
• IR remote controller (REMC)
• A/D converter (ADC10)
• Interrupt controller (ITC) (PCLK is used only when the register is set.)
PCLK is not required for the peripheral modules/functions shown below.
Peripheral circuits/functions that do not use PCLK
• Clock timer (CT)
• Stopwatch timer (SWT)
• Watchdog timer (WDT)
• 8-bit OSC1 timer (T8OSC1)
• LCD driver (LCD)
• R/F converter (RFC)
• 16-bit PWM timer (T16A2)
• FOUTH/FOUT1 outputs
Table B.1.1 shows a list of methods for clock control and starting/stopping the CPU.
1.1 Clock Control List
Table B.
Current
consumption
OSC1
iOSC/OSC3
CPu (CClK)
PClK
peripheral
OSC1
peripheral
CPu stop
method
CPu startup
method
↑
Low
Stop
Stop
Stop
Stop
Stop
Execute
slp
instruction
1
Oscillation
(system CLK)
Stop
Stop
Stop
Stop
Execute
slp
instruction
1, 2
Oscillation
(system CLK)
Stop
Stop
Stop
Run
Execute
halt
instruction
1, 2, 3, 4
Oscillation
(system CLK)
Stop
Stop
Run
Run
Execute
halt
instruction
1, 2, 3, 4
Oscillation
(system CLK)
Stop
Run
(1/1)
Run
Run
Oscillation
Oscillation
(system CLK)
Stop
Run
Run
Execute
halt
instruction
1, 2, 3, 4
Oscillation
Oscillation
(system CLK)
Run
(low gear)
Run
Run
High
↓
Oscillation
Oscillation
(system CLK)
Run
(1/1)
Run
Run
HALT and SLEEP mode cancelation methods (CPU startup method)
1. Startup by port
Started up by an I/O port or debug interrupt (ICD forced break).
2. Startup by RTC (S1C17624/604)
Started up by an RTC interrupt.
3. Startup by OSC1 peripheral circuit
Started up by a clock timer, stopwatch timer, 8-bit OSC1 timer, or watchdog timer interrupt.
4. Startup by PCLK peripheral circuit
Started up by a PCLK peripheral circuit interrupt.
Reducing Power Consumption via Power Supply Control
B.2
The available power supply controls are listed below.
internal voltage regulator
• Setting the internal operating voltage V
D1
to 2.5 V increases current consumption.
For normal operations, set V
D1
to 1.8 V, and switch to 2.5 V only for Flash memory programming.
• Note that turning on internal voltage regulator heavy load protection will increase current consumption.
Turn off heavy load protection for normal operations. Turn on only if operations are unstable.