SWCU185G January 2018 – June 2024 CC1312PSIP , CC1312R , CC1352P , CC1352R , CC2642R , CC2642R-Q1 , CC2652P , CC2652PSIP , CC2652R , CC2652RB , CC2652RSIP , CC2662R-Q1
Shutdown mode is defined as having no active power regulator in the CC13x2 and CC26x2 device platform. It is not recommended to use shutdown as a power mode to conserve power during normal operation of the device.
Before putting the CC13x2 and CC26x2 device platform in shutdown mode, I/O pins are latched to keep their output values in shutdown—this is the only difference between holding the devices in reset with the reset pin and shutdown mode.
Only an enabled pin interrupt or reset pin can wake up the CC13x2 and CC26x2 device platform from shutdown mode.
A wake-up event to wake up from shutdown is not detected until the device reaches shutdown. Wake-up events happening after a shutdown is initiated but before actual shutdown are not captured and thus will not cause the device to wake up.
Description | Register | Required Step |
---|---|---|
Configure the wake-up pin | IOC:IOCFGxx.WU_CFG | Yes |
Synchronize transactions to AON domain | AON_RTC.SYNC | Yes (Read register) |
Enable shutdown and latch I/Os | AON_PMCTL:SHUTDOWN.EN | Yes |
Stop the system CPU to start the power-down sequence | WFI or WFE | Yes |
The IO pads are level sensitive when configured for wake up from shutdown (IOC:IOFGxx.WU_CFG). An internal signal is generated from the pad when the input level matches the set level (WU_CFG - 10: LOW, - 11: HIGH).
If several pins are configured for wake up from shutdown, careful consideration must be taken to allow proper triggering of the wake up event. Since signals from the IO pads are internally OR'ed together to form a single signal routed to an internal edge trigger block, when one of the input signals remains active there will be no edge signal on the internal edge detect block until the active input is released. In other words, if a pin is held active (HIGH or LOW, depending on configuration), the other pins will not generate a wake up event until the first pin is released or made inactive.