Texas Instruments CC2650DK Benutzerhandbuch
Power Management
When AUX_PD is in active mode, the device is prevented from entering Standby or Shutdown power
modes, as AUX_PD is requesting system resources from the supply system.
modes, as AUX_PD is requesting system resources from the supply system.
17.5.2.2 Power Down
Power down is requested when AUX has been disconnected from the system BUS.
In power down mode, AUX_PD is on and the sensor controller can still execute programs. The AUX
domain receives a clock defined in [AON_WUC:AUXCLK:PWR_DWN_SRC].
domain receives a clock defined in [AON_WUC:AUXCLK:PWR_DWN_SRC].
To have AUX enter power-down mode, a 4-phase handshake with the AON WUC is necessary, using the
[AUX_WUC] register bank by doing the following sequence:
[AUX_WUC] register bank by doing the following sequence:
•
Write [AUX_WUC:PWRDWNREQ] = 1
•
Wait for [AUX_WUC:PWRDWNACK] =1
•
Write [AUX_WUC:PWRDWNREQ] = 0
•
Wait until [AUX_WUC:PWRDWNACK] =0
When PWRDWNACK goes low, AUX will start receiving the power-down clock instead of the active-mode
clock.
clock.
By default, the entire AUX domain has full retention in this mode. TI recommends using this low-power
mode, to save execution time by not having to reconfigure AUX every time it is used.
mode, to save execution time by not having to reconfigure AUX every time it is used.
If the entire CC26XX device must be put in a low-power mode, AUX must first disconnect from the MCU
system bus before doing its power-down sequence. Refer to
system bus before doing its power-down sequence. Refer to
, MCU Bus Connection for
more details.
17.5.2.3 Power Off
The AUX domain can also be fully powered off (power disconnected) from the domain to reduce the
leakage current from the domain. To do this, the system must first disconnect from the MCU system bus
(refer to
leakage current from the domain. To do this, the system must first disconnect from the MCU system bus
(refer to
, MCU Bus Connection for more details).
To request the domain to be powered off, write [AON_WUC:PWROFFREQ]=1.
Even if the entire domain is powered off, the contents of AUX SRAM are retained by default. This is
configurable in the register field [AON_WUC:AUXCFG:SRAM_RET_EN].
configurable in the register field [AON_WUC:AUXCFG:SRAM_RET_EN].
NOTE:
Powering off the entire AUX domain is usually not needed, as the extra current being drawn
compared to power down is minimal (just a few nA).
17.5.3 Wakeup Events
The AON domain can generate different wakeup events that set the AUX domain into active mode again:
•
Up to 4 events configured in [AON_EVENT:AUXWUSEL]
•
A software-triggered event from AON triggered by writing to [AON_WUC:AUXCTL:SWEV]
•
Setting [AON_WUC:AUXCTL:AUX_FORCE_ON]=1
If code running on the system CPU accesses AUX, the [AON_WUC:AUXCTL:AUX_FORCE_ON] bit
should always be set. This ensures that AUX is running in active mode, and connects to the MCU system
bus. AUX should not be accessed from the MCU domain before the status register field
[AON_WUC:PWRSTAT:AUX_PD_ON] has been asserted.
should always be set. This ensures that AUX is running in active mode, and connects to the MCU system
bus. AUX should not be accessed from the MCU domain before the status register field
[AON_WUC:PWRSTAT:AUX_PD_ON] has been asserted.
Any power-down request remaining from before AUX was powered down will take effect again when the
wakeup source bits are cleared, by clearing the event flag at the source of the event.
wakeup source bits are cleared, by clearing the event flag at the source of the event.
The current status of the wakeup events can be read from [AUX_WUC:WUEVFLAGS]. The event flags
that can be read out are:
that can be read out are:
•
AON_RTC channel 2
•
Software event from AON
1209
SWCU117A – February 2015 – Revised March 2015
AUX – Sensor Controller with Digital and Analog Peripherals
Copyright © 2015, Texas Instruments Incorporated