User’s Manual U14272EJ3V0UM
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CHAPTER 10 POWER MANAGEMENT UNIT (PMU)
This chapter describes the Power Management Unit (PMU) operation, register settings and power modes.
10.1 General
The PMU performs power management within the V
R
4181 and controls the power supply throughout the system.
The PMU provides the following functions:
•
Reset control
•
Shutdown control
•
Power-on control
•
Low-power mode control
10.2 V
R
4181 Power Mode
This section describes the V
R
4181 power modes in detail. The V
R
4181 supports the following four power modes:
•
Fullspeed mode
•
Standby mode
•
Suspend mode
•
Hibernate mode
10.2.1 Power mode and state transition
The V
R
4181 transits from Fullspeed mode to Standby mode, Suspend mode, or Hibernate mode by executing a
STANBY, SUSPEND, or HIBERNATE instruction respectively. An RTC reset is always valid in every mode, and
initializes (resets) units in the V
R
4181 including the RTC.
The figure on the following page, Figure 10-1, is a conceptual diagram showing the interaction and control of the
four power modes of the V
R
4181.