15.1.2 Modes of operation
The LLWU module becomes functional on entry into a low-leakage power mode. After
recovery from LLS, the LLWU is immediately disabled. After recovery from VLLS, the
LLWU continues to detect wakeup events until the user has acknowledged the wakeup
via a write to the PMC_REGSC[ACKISO] bit.
15.1.2.1 LLS mode
The LLWU module provides up to 16 external wakeup inputs and up to 8 internal module
wakeup inputs.
Wakeup events due to external wakeup inputs and internal module wakeup inputs result
in an interrupt flow when exiting LLS.
NOTE
The LLWU interrupt must not be masked by the interrupt
controller to avoid a scenario where the system does not fully
exit Stop mode on an LLS recovery.
15.1.2.2 VLLS modes
The LLWU module provides up to 16 external wakeup inputs and up to 8 internal module
wakeup inputs. All wakeup events result in VLLS exit via a reset flow.
15.1.2.3 Non-low leakage modes
The LLWU is not active in all non-low leakage modes where detection and control logic
are in a static state. The LLWU registers are accessible in non-low leakage modes and are
available for configuring and reading status when bus transactions are possible.
When the wakeup pin filters are enabled, filter operation begins immediately. If a low
leakage mode is entered within 5 LPO clock cycles of an active edge, the edge event will
be detected by the LLWU.
Introduction
KL25 Sub-Family Reference Manual, Rev. 3, September 2012
246 Freescale Semiconductor, Inc.
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