sdk17 with nrf52832 : pwr_mgmt

[xiaobai]

I want to use this routine to complete a radio project with low power consumption, but I find that the system is always shut down. Could you please tell me how to modify it so that the system can only enter the sleep state instead of shutting down the system?This way, some of my own timer - triggered functions can run.Sorry for the trouble, please kindly comment!

[Jørgen Holmefjord]

Hi,

Which exact function(s) are you calling, and what do you mean by "shut down"? Does the chip enter System OFF mode?

Regarding the clocks, the main difference I can see is that #1 starts the HFCLK in addition to LFCLK, while #2 only starts LFCLK. Also, nrf_drv_clock will use configuration from your sdk_config.h file for LFCLK source, while you set it directly in #1.

Best regards,
Jørgen

[xiaobai]

To use radio, you must turn on the HFCLK clock.That if I I want to the use of ultra low power radio function, you can do it: the system clock, before initialization initialize LFCLK clock, only using radio function open HFCLK clock (need to set aside time for), using HFCLK the radio function at the same time shut down after the completion of the clock (don't have to set aside time for), then calls the power management function into low power mode.

Please kindly give me a reply as to whether my above approach is feasible. Thank you

[Jørgen Holmefjord]

Note sure I understand your questions, but you can stop the HFXO clock between radio events, and use RTC (running off LFCLK) to wakeup the chip in the future, then put the chip into system ON sleep mode.

[xiaobai]

Well, according to what you say, what I'm going to do should work.I turn on the HFCLK clock when I want to use the radio function;When I don't need to use the radio, turn off HFCLK (LFCLK is always on).

[xiaobai]

Another question is, do I have to allow time for both when I turn on and off the HFCLK clock?

[Jørgen Holmefjord]

To be fully correct, the HF crystal is required for radio operations. The internal HF clock (HFINT) will be started automatically whenever a peripheral or the CPU requires it.

You only need to set aside time for the clock to start, since it needs to be started before you start the radio operations. When you stop the clock, you do not care when it stops, that just takes the time it takes.