Zephyr ncs sleep modes

Zephyr and Nordic ncs Sleep Modes 2022-01-15 Tuesday

Some posts and links to follow:

• https://devzone.nordicsemi.com/f/nordic-q-a/83227/how-to-put-nrf52832-into-a-deep-sleep-mode-for-some-amount-of-time-as-well-as-wake-it-up-from-deep-sleep-mode-which-header-file-contains-all-these-functionalities/345474#345474
And from this post, note however these forum replies are for Nordic nRF5x family parts:
• https://devzone.nordicsemi.com/f/nordic-q-a/51648/how-to-put-nrf52840-to-deep-sleep-system-off/207410#207410 post ~two years ago (2019) by Nordic Semi Amanda Hsieh
• https://infocenter.nordicsemi.com/index.jsp?topic=%2Fcom.nordic.infocenter.nrf52832.ps.v1.1%2Fpower.html&cp=4_2_0_17_1&anchor=unique_2047546596

Looking now more closely at nRF9160 System in Package (SiP):

• https://infocenter.nordicsemi.com/topic/nwp_041/WP/nwp_041/sleep_types/flight_mode_sleep.html
• https://infocenter.nordicsemi.com/topic/nwp_041/WP/nwp_041/example_sequences/uplink_data_psm.html
• https://infocenter.nordicsemi.com/topic/ps_nrf9160/product_overview.html
• https://infocenter.nordicsemi.com/topic/ps_nrf9160/chapters/current_consumption/doc/frontpage.html

Oh and a note on nRF9160 watchdog timer:

• https://infocenter.nordicsemi.com/topic/ps_nrf9160/wdt.html

This looks important:

• https://devzone.nordicsemi.com/f/nordic-q-a/81744/nrf9160-deep-sleep-power-consumption-help

^ 2022-02-17 Thursday

Continuing the search at https://nordicsemi.com with pattern "nRF9160 application processor", first a news press then the downloads page for this SiP:

• https://www.nordicsemi.com/News/2020/09/Crosby-Technologies-employs-nRF9160
• https://www.nordicsemi.com/Products/Development-hardware/nRF9160-DK/Download

• https://www.nordicsemi.com/Products/nRF9160/GetStarted

^ nRF9160 Sleep Mode Forum Posts

nRF9160 sleep mode not working in SDK 'nrf' v1.6.1, works in 1.7.0 . . .

• https://devzone.nordicsemi.com/f/nordic-q-a/80282/nrf9160-sleep-mode

Symbol 'PSM' may be a more apt symbol for which to search, also looks like power savings modes may only be practical with certain network providers:

• https://devzone.nordicsemi.com/f/nordic-q-a/63702/testing-power-saving-mode-psm-on-nrf9160

2022-02-16 WED - Inquiring at CircuitDojo about where to find low power, sleep and deep sleep mode settings, APIs for these in nRF9160 based designs:

• https://community.jaredwolff.com/d/222-nrf9160-sleep-and-low-power-control-areas

In first reply a recommendation to review `nfed` sample application named 'active_sleep':

• https://github.com/circuitdojo/nrf9160-feather-examples-and-drivers/blob/v1.7.x/samples/active_sleep/child_image/spm.conf

^ nRF9160 Power Saving Mode(s) Examples

Power Savings Mode Ten Minutes Period Example

• https://devzone.nordicsemi.com/guides/cellular-iot-guides/b/hardware-design/posts/measuring-psm-idle-current-on-the-nrf91-dk

Excerpts from this post:

"In order to achieve the lowest possible current consumption, logging has to be turned off. This is done by,

Adding the CONFIG_SERIAL=n flag to the prj.conf file in the project folder.
Adding the CONFIG_SERIAL=n to the SPM prj.conf file. This is located in the SDK_ROOT/nrf/samples/nrf9160/spm folder."

An example from Jared Wolff of CircuitDojo, see line 135 in main.c:

• https://github.com/circuitdojo/nrf9160-feather-examples-and-drivers/blob/v1.7.x/samples/deep_sleep/src/main.c

Zephyr Project documentation regarding `k_cpu_idle()`:

• https://docs.zephyrproject.org/2.6.0/reference/kernel/other/cpu_idle.html?highlight=k_cpu_idle

^ Terms

There are a lot of terms and acronyms associated with LTE modem and Nordic Semi SoC and SiP parts. Here we capture a few of those in our quest for low power modes understanding.

• UICC . . . Universal Integrated Circuit Card
• eDRX . . . Extended Discontinuous Reception
Found mention of eDRX while searching Nordic Devzone forum for 'UICC': https://devzone.nordicsemi.com/f/nordic-q-a/76896/rerouting-at-interface-for-power-measurement-using-external-supply/318244#318244

^ Pattern Searches in Zephyr and NRF Repositories

Some searches whose results to further explore . . .

ted@localhost:~/projects/zephyr-based/zephyr$ grep -nr sleeping ./*
./arch/arm/core/aarch32/cpu_idle.S:125:	 * Lock PRIMASK while sleeping: wfe will still get interrupted by
./arch/arm/core/aarch32/nmi_on_reset.S:12: * is to hard hang, sleeping.
./boards/posix/native_posix/doc/index.rst:56:simulated CPU is sleeping.
./doc/guides/porting/arch.rst:226:yielding/sleeping primitives.