K60P100M100SF2RM Datasheet, PDF (335/1809 Pages) Freescale Semiconductor, Inc – K60 Sub-Family Reference Manual

Chapter 15
Low-leakage wake-up unit (LLWU)
15.1 Introduction
NOTE
For the chip-specific implementation details of this module's
instances see the chip configuration chapter.
The LLWU module allows the user to select up to 16 external pin sources and up to 7
internal modules as a wakeup source from low-leakage power modes (LLS and VLLS).
The input sources vary by device and are described in the specific device's Chip
Configuration details. Each of the available wakeup 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 both LLS and VLLS through a reset flow. On MCUs
where the RESET pin is shared with other functions, the explicit port mux control
register must be set for RESET pin before the RESET pin can be used as a low-leakage
reset source.
When in LLS mode, the I/O are released immediately on a wakeup or reset event. In the
case of LLS exit via a RESET pin, the I/O default to their reset state.
When in VLLS modes, the I/O states are held on a wakeup event until the wakeup has
been acknowledged via a write to the ACKISO bit. In the case of VLLS exit via a RESET
pin, the I/O are released and default to their reset state. In this case, no write to the
ACKISO is needed.
In both LLS mode exits via RESET pin and any VLLS mode via a wakeup or reset event,
the MC_SRS[WAKEUP] is set indicating the low-leakage mode was active prior to the
last system reset flow. Using the RESET pin to trigger an exit from LLS or VLLS results
in the MC_SRS[PIN] being set as well.
The LLWU module also includes two optional digital pin filters. One for the external
wakeup pins combined and one for the RESET pin.
K60 Sub-Family Reference Manual, Rev. 6, Nov 2011
Freescale Semiconductor, Inc.
335