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Table 14-2. Power mode transition triggers (continued)
Transition #
10
11
1. If debug is enabled, the core clock remains to support debug.
2. If PMCTRL[STOPM]=000 and STOPCTRL[PSTOPO]=01 or 10, then only a Partial Stop mode is entered instead of STOP
3. If PMCTRL[STOPM]=000 and STOPCTRL[PSTOPO]=00, then VLPS mode is entered instead of STOP. If
PMCTRL[STOPM]=000 and STOPCTRL[PSTOPO]=01 or 10, then only a Partial Stop mode is entered instead of VLPS
14.5.2 Power mode entry/exit sequencing
When entering or exiting low-power modes, the system must conform to an orderly
sequence to manage transitions safely.
The SMC manages the system's entry into and exit from all power modes. This diagram
illustrates the connections of the SMC with other system components in the chip that are
necessary to sequence the system through all power modes.
Figure 14-2. Low-power system components and connections
14.5.2.1 Stop mode entry sequence
Entry into a low-power stop mode (Stop, VLPS, LLS, VLLSx) is initiated by a CPU
executing the WFI instruction. After the instruction is executed, the following sequence
occurs:
1. The CPU clock is gated off immediately.
2. Requests are made to all non-CPU bus masters to enter Stop mode.
3. After all masters have acknowledged they are ready to enter Stop mode, requests are
made to all bus slaves to enter Stop mode.
4. After all slaves have acknowledged they are ready to enter Stop mode, all system and
bus clocks are gated off.
5. Clock generators are disabled in the MCG.
6. The on-chip regulator in the PMC and internal power switches are configured to
meet the power consumption goals for the targeted low-power mode.
Freescale Semiconductor, Inc.
From
To
RUN
LLSx
LLSx
RUN
VLPR
LLSx
KL27 Sub-Family Reference Manual , Rev. 5, 01/2016
Chapter 14 System Mode Controller (SMC)
Trigger conditions
PMPROT[ALLS]=1, PMCTRL[STOPM]=011,
STOPCTRL[LLSM]=x (LLSx), Sleep-now or sleep-on-exit
modes entered with SLEEPDEEP set, which is controlled in
System Control Register in ARM core.
Wakeup from enabled LLWU input source or
RESET pin.
PMPROT[ALLS]=1, PMCTRL[STOPM]=011, Sleep-now or
sleep-on-exit modes entered with SLEEPDEEP set, which is
controlled in System Control Register in ARM core.
233
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