Memory Map And Register Descriptions - NXP Semiconductors MKL27Z128VFM4 Reference Manual

Mode
VLPW The core clock is gated off. The system, bus, and flash clocks continue to operate, although their
maximum frequency is restricted. See the Power Management chapter for details on the maximum
allowable frequencies.
VLPS The core clock is gated off. System clocks to other masters and bus clocks are gated off after all
stop acknowledge signals from supporting peripherals are valid.
LLS The core clock is gated off. System clocks to other masters and bus clocks are gated off after all
stop acknowledge signals from supporting peripherals are valid. The MCU is placed in a low
leakage mode by reducing the voltage to internal logic. All system RAM contents, internal logic and
I/O states are retained.
VLLS3 The core clock is gated off. System clocks to other masters and bus clocks are gated off after all
stop acknowledge signals from supporting peripherals are valid. The MCU is placed in a low
leakage mode by powering down the internal logic. All system RAM contents are retained and I/O
states are held. Internal logic states are not retained.
VLLS1 The core clock is gated off. System clocks to other masters and bus clocks are gated off after all
stop acknowledge signals from supporting peripherals are valid. The MCU is placed in a low
leakage mode by powering down the internal logic and all system RAM. I/O states are held. Internal
logic states are not retained.
VLLS0 The core clock is gated off. System clocks to other masters and bus clocks are gated off after all
stop acknowledge signals from supporting peripherals are valid. The MCU is placed in a low
leakage mode by powering down the internal logic and all system RAM. I/O states are held. Internal
logic states are not retained. The 1kHz LPO clock is disabled and the power on reset (POR) circuit
can be optionally enabled using STOPCTRL[PORPO].

14.4 Memory map and register descriptions

Information about the registers related to the system mode controller can be found here.
Different SMC registers reset on different reset types. Each register's description provides
details. For more information about the types of reset on this chip, refer to the Reset
section details.
The SMC registers can be written only in supervisor mode.
Write accesses in user mode are blocked and will result in a bus
error.
Before executing the WFI instruction, the last register written to
must be read back. This ensures that all register writes
associated with setting up the low power mode being entered
have completed before the MCU enters the low power mode.
Failure to do this may result in the low power mode not being
entered correctly.
Freescale Semiconductor, Inc.
Table 14-1. Power modes (continued)
NOTE
NOTE
KL27 Sub-Family Reference Manual , Rev. 5, 01/2016
Chapter 14 System Mode Controller (SMC)
Description
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