SW runs slower without Debugger

RE: SW runs slower without Debugger

Vidar Berg — Mon, 20 Nov 2023 13:58:03 GMT

You can use the CRITICAL_REGION_ENTER and CRITICAL_REGION_EXIT macros for this. If you use critical sections, it is recommended to apply this change recommended in the Softdevice release notes:

RE: SW runs slower without Debugger

pungent1188 — Mon, 20 Nov 2023 13:47:25 GMT

What shall I use instead of NVIC_DisableIRQ / NVIC_EnableIRQ when SD is enabled?

S112_SDS_v3.1 doesn't say explicitly.

RE: SW runs slower without Debugger

Vidar Berg — Mon, 20 Nov 2023 12:08:14 GMT

Thanks for confirming. Yes, it's not necessary continuously poll SD events. The app will poll events from the softdevice after receiving the Softdevice interrupt in the SoftDevice Handler library.

[quote userid="129638" url="~/f/nordic-q-a/105798/sw-runs-slower-without-debugger/456369"]What if I need to disable interrupt for some time in critical section? Will BLE tolerate missed events?[/quote]

You can not disable interrupts globally as this will break the real time requirements of the stack. You can safely mask application level interrupts, but not Softdevice interrupts.

[quote userid="129638" url="~/f/nordic-q-a/105798/sw-runs-slower-without-debugger/456369"]Although it's weird that basic beacon example has power saving, since power saving is not an easy topic and usually comes after main functionality works in the project.[/quote]

It's designed to be easy on this chip. Most of the power management is automatically handled in hardware, and usually it is sufficient to just call nrf_pwr_mgmt_run() from the main loop.

RE: SW runs slower without Debugger

pungent1188 — Mon, 20 Nov 2023 11:26:33 GMT

Thank you that worked.

Does that mean BLE stack does not need high frequency polling from while(1) loop, and all communication is interrupt based?

What if I need to disable interrupt for some time in critical section? Will BLE tolerate missed events?

Although it's weird that basic beacon example has power saving, since power saving is not an easy topic and usually comes after main functionality works in the project.

And there is no comment near nrf_pwr_mgmt_run saying it goes to sleep.

RE: SW runs slower without Debugger

Vidar Berg — Mon, 20 Nov 2023 10:58:57 GMT

The program enters sleep (System ON mode) between events when idle_state_handle()->nrf_pwr_mgmt_run() is called from the main loop. And the Systick timer will be paused when the system is in sleep mode, unless the chip is in debug interface mode.

You can confirm this by commenting the nrf_pwr_mgmt_run() function.

RE: SW runs slower without Debugger

pungent1188 — Mon, 20 Nov 2023 10:52:52 GMT

Thank you for your reply,

I was able to reproduce it using the example code, attaching here, could you try it?

devzone.nordicsemi.com/.../beacon_5F00_wrong_5F00_systick.zip

Systick does work, only 315x slower without debugger. There is no low power used as far as I can tell.

To be run on nrf52 board with s112 softdevice. It's configured as NRF52810.

Please scope on pin19.

Last init command is: sd_ble_gap_adv_start

Then in the infinite loop nrf_pwr_mgmt_run();

Also why program stops when I detach with Jlink, it's unusual.

RE: SW runs slower without Debugger

Vidar Berg — Fri, 17 Nov 2023 14:19:26 GMT

Hello,

The ARM cortex systick timer is only running when the CPU is active or when the chip is debug interface. If you need a low power systick source, we recommend using the RTC tick event: TICK event

CPU

[quote user=""]no WFI in mainloop[/quote]

Is there anything else called from the main loop that may cause the chip to enter sleep (System ON mode)?

Best regards,

Vidar