Modes Of Operation - NXP Semiconductors freescale KV4 Series Reference Manual

Introduction
1. Requires the peripheral and the peripheral interrupt to be enabled. The LLWU's WUME bit enables the internal module flag
as a wakeup input. After wakeup, the flags are cleared based on the peripheral clearing mechanism.
19.2 Introduction
The LLWU module allows the user to select up to 32 external pins and up to 8 internal
modules as interrupt wake-up sources from low-leakage power modes.
The input sources are described in the device's chip configuration details. Each of the
available wake-up sources can be individually enabled.
The RESET pin is an additional source for triggering an exit from low-leakage power
modes, and causes the MCU to exit VLLS through a reset flow.
The LLWU module also includes four optional digital pin filters for the external wakeup
pins.
See AN4503: Power Management for Kinetis and ColdFire+ MCUs
using the LLWU.
19.2.1 Features
The LLWU module features include:
• Support for up to 32 external input pins and up to 8 internal modules with individual
enable bits for MCU interrupt from low leakage modes
• Input sources may be external pins or from internal peripherals capable of running in
VLLS. See the chip configuration information for wakeup input sources for this
device.
• External pin wake-up inputs, each of which is programmable as falling-edge, rising-
edge, or any change
• Wake-up inputs that are activated after MCU enters a low-leakage power mode
• Optional digital filters provided to qualify an external pin detect. Note that when the
LPO clock is disabled, the filters are disabled and bypassed.

19.2.2 Modes of operation

The LLWU module becomes functional on entry into a low-leakage power mode. After
recovery from VLLS, the LLWU continues to detect wake-up events until the user has
acknowledged the wake-up via a write to PMC_REGSC[ACKISO].
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KV4x Reference Manual, Rev. 2, 02/2015
Preliminary
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