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1.4.9 Power modes
The V
4181 supports four power modes: Fullspeed mode, Standby mode, Suspend mode, and Hibernate mode. A
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detailed description of these power modes is also given in CHAPTER 10 POWER MANAGEMENT UNIT (PMU).
(1) Fullspeed mode
This is the normal operation mode.
The V
4181's default status sets operation under Fullspeed mode. After a reset, the V
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mode.
(2) Standby mode
When a STANDBY instruction has been executed, the processor can be set to Standby mode. During Standby
mode, the pipeline clock (PClock) in the CPU core is held at high level. The peripheral units all operate as they
do during Fullspeed mode. This means that DMA operations are enabled during Standby mode.
During Standby mode, the processor returns to Fullspeed mode if any interrupt request occurs.
(3) Suspend mode
When the SUSPEND instruction has been executed, the processor can be set to Suspend mode. During
Suspend mode, the pipeline clock (PClock) in the CPU core is held at high level. The V
supplying TClock and PCLK to peripheral units. While in this mode, the register and cache contents are retained.
Contents of DRAM can also be retained by putting DRAM into self-refresh mode.
During Suspend mode, the processor returns to Fullspeed mode if any of power-on factors or some of interrupt
requests occurs.
(4) Hibernate mode
When the HIBERNATE instruction has been executed, the processor can be set to Hibernate mode. During
Hibernate mode, clocks other than the RTC clock (32.768 kHz) are held at high level and the PLL stops. While in
this mode, contents of the registers and caches are not retained. Contents of DRAM can be retained by putting
DRAM into self-refresh mode.
Power consumption during Hibernate mode is about 0 W if power to 2.5 V power supply is not applied (it does
not go completely to 0 W due to the existence of a 32.768 kHz oscillator or on-chip peripheral circuits that
operate at 32.768 kHz).
During Hibernate mode, the processor returns to Fullspeed mode if any of power-on factors or some of interrupt
requests occurs.
CHAPTER 1 INTRODUCTION
User's Manual U14272EJ3V0UM
4181 returns to Fullspeed
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4181 also stops
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