下载
1 Introduction
Applications strive for high performance within constrained
energy budgets. Increasing system level requirements does not
allow for compromises on performance, but pushes for low
energy budgets to extend product use times. The Kinetis
microcontroller family includes internal power management
features that can be used to control the microcontroller's
power usage and assist reaching the targets of embedded
designs.
This application note discusses how to use the power
management systems, provides use case examples, and shows
real-time current measurement results for these use cases. A
section on how to use the DDR memory controller to maintain
the low power nature of your application is in this release.
Also included is a discussion of the differences between power
management features on the various microcontrollers, along
with drivers demonstrating these low-power states.Tips are
given for using each of the power modes.
Power management methods discussed here do not include
details on the clock generator module. Refer to the MCU
reference manual for a description of the clock modes as well
as the explanation of Multipurpose Clock Generator(MCG)
acronyms. This application note focuses on the Power
Management Controller (PMC), the Low Leakage Wakeup
Unit (LLWU), the Reset Control Module (RCM), and the
System Mode Controller (SMC).
Freescale Semiconductor
Document Number: AN4503
Application Note
Rev. 2, 04/2015
Power Management for Kinetis
MCUs
When and how to use Kinetis low-power modes
© 2015 Freescale Semiconductor, Inc.
Contents
1 Introduction.............................. .............................. 1
2 Power Management Techniques............................. 3
3 Quick Start Kinetis SDK....................................... 18
4 Quick Start............................................................ 24
5 Reset Management................................................27
6 Dynamic and Static Power
Management......................................... ................ 30
7 Clock Operation in Low-power Modes ................31
8 Power Mode Transitions.......................................35
9 Power Mode Entry Code................. ..................... 38
10 Power Mode Exit Transitions............ ................... 50
11 Modules in Power Modes..................................... 52
12 Using external memories and peripherals -
Use case with DDR Memory Controller and
DDR Low Power Modes.............................. ........ 59
13 Power Measurement..................... ........................ 61
14 LLWU pin and module Wakeup........ .................. 65
15 References and Revision History.......................... 67
