9. EMU - Energy Management Unit
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Quick Facts
What?
The EMU (Energy Management Unit) handles the
different low energy modes in EFM32 Jade Gecko
Why?
The need for performance and peripheral functions
varies over time in most applications. By efficiently
scaling the available resources in real-time to match
the demands of the application, the energy con-
sumption can be kept at a minimum.
How?
With a broad selection of energy modes, a high
number of low-energy peripherals available even in
EM2 DeepSleep, and short wake-up time (2 µs from
EM2 DeepSleep and EM3 Stop), applications can
dynamically minimize energy consumption during
program execution.
9.1 Introduction
The Energy Management Unit (EMU) manages all the low energy modes (EM) in EFM32 Jade Gecko. Each energy mode manages if
the CPU and the various peripherals are available. The energy modes range from EM0 Active to EM4 Shutoff. EM0 Active mode pro-
vides the highest amount of features, enabling the CPU, and peripherals with the highest clock frequency. EM4 Shutoff Mode provides
the lowest power state, allowing the part to return to EM0 Active on a wakeup condition. The EMU also controls the various power
routing configurations, internal regulators settings, and voltage monitoring needed for optimal power configuration and protection.
9.2 Features
The primary features of the EMU are listed below:
• Energy Modes control
• Entry into EM4 Hibernate or EM4 Shutoff
• Configuration of regulators and clocks for each Energy Mode
• Configuration of various EM4 Hibernate/Shutoff wakeup conditions
• Configuration of RAM power and retention settings
• Configuration of GPIO retention settings
• Power routing configurations
• DCDC control
• Internal power switches allowing for extensible system power architecture
• Temperature measurement control and status
• Brown Out Detection
• Voltage Monitoring
• Four dedicated continuous monitor channels
• Optional monitor features include interrupt generation, low power mode wakeup, and EM4 Entry
• State Retention
EFM32JG1 Reference Manual
EMU - Energy Management Unit
silabs.com
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