
Table 16-1. Power modes (continued)
Mode
Description
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.
VLLS2
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 the system RAM3 partition. The system RAM2
partition can be optionally retained using STOPCTRL[RAM2PO]. The system RAM1 partition
contents are retained in this mode. 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].
1. See the devices' chip configuration details for the size and location of the system RAM partitions.
16.3 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.
NOTE
The SMC registers can be written only in supervisor mode.
Write accesses in user mode are blocked and will result in a bus
error.
NOTE
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.
Chapter 16 System Mode Controller (SMC)
KV4x Reference Manual, Rev. 2, 02/2015
Freescale Semiconductor, Inc.
Preliminary
267
Summary of Contents for freescale KV4 Series
Page 2: ...KV4x Reference Manual Rev 2 02 2015 2 Preliminary Freescale Semiconductor Inc...
Page 60: ...KV4x Reference Manual Rev 2 02 2015 60 Preliminary Freescale Semiconductor Inc...
Page 128: ...Debug Security KV4x Reference Manual Rev 2 02 2015 128 Preliminary Freescale Semiconductor Inc...
Page 138: ...Boot KV4x Reference Manual Rev 2 02 2015 138 Preliminary Freescale Semiconductor Inc...
Page 1358: ...KV4x Reference Manual Rev 2 02 2015 1358 Preliminary Freescale Semiconductor Inc...