Power Mode Selection
436
SLAU356I – March 2015 – Revised June 2019
Copyright © 2015–2019, Texas Instruments Incorporated
Power Control Manager (PCM)
•
Active Mode Request (AMR) : Used to change from one active mode to another.
•
Low-Power Mode Request (LPMR) : Used to enter LPM3, LPM4, LPM3.5, and LPM4.5 modes.
AMR has the higher priority over the LPMR settings. LPM3, LPM4, LPM3.5, and LPM4.5 modes are
entered if the proper values are written into LPMR regardless of the AMR settings. If there is a change to
LPMR and AMR that happens together along with SLEEPDEEP, the PCM first performs the AMR change
and then enters into LPM3, LPM4, LPM3.5, or LPM4.5
The PCMCTL0 register is key protected for write access. This protects against inadvertent writes changing
the power mode settings. Read access of the PCMCTL0 is always possible and does not require a key.
The Current Power Mode (CPM) bits in the PCMCTL0 register are read only and reflect the current power
mode of the system. CPM is updated when a power mode request completes.
8.9
Power Mode Selection
summarizes the various power modes available, the appropriate PCMCTL0 settings, and the
entry mechanism for each of the modes.
(1)
X = don't care
Table 8-3. Power Mode Selection
(1)
Mode
Description
PCMCTL0
SLEEPDEEP
Entry Mechanism
AMR[3:0]
LPMR[3:0]
AM_LDO_VCORE0
Active mode
Core voltage level 0
LDO operation
0h
X
0
Writing of AMR register
AM_LDO_VCORE1
Active mode
Core voltage level 1
LDO operation
1h
X
0
AM_DCDC_VCORE0
Active mode
Core voltage level 0
DC/DC operation
4h
X
0
AM_DCDC_VCORE1
Active mode
Core voltage level 1
DC/DC operation
5h
X
0
AM_LF_VCORE0
Low-frequency active mode
Core voltage level 0
LDO operation
8h
X
0
AM_LF_VCORE1
Low-frequency active mode
Core voltage level 1
LDO operation
9h
X
0
LPM0_LDO_VCORE0
LPM0 modes
Core voltage level same as
respective active mode
Same as the
corresponding
active mode.
Programing
AMR is not a
prerequisite
for the device
to enter
LPM0.
X
0
WFI, WFE, Sleep-on-exit
LPM0_DCDC_VCORE0
LPM0_LF_VCORE0
LPM0_LDO_VCORE1
LPM0_DCDC_VCORE1
LPM0_LF_VCORE1
LPM3
LPM3, LPM4 modes
Core voltage level same as
respective active mode
X
0h
1
WFI, WFE, Sleep-on-exit
LPM4
LPM3.5
LPM3.5 mode
Core voltage level 0
X
Ah
1
WFI, WFE, Sleep-on-exit
LPM4.5
LPM4.5 mode
Core voltage turned off
X
Ch
1
WFI, WFE, Sleep-on-exit