Soft reset (sd_nvic_SystemReset() ) timing

[ned_zeppelin]

How long does it take to perform a soft reset (using sd_nvic_SystemReset()/NVIC_SystemReset())?

Looking at power measurements (attached) it seems to take about 730 ms (+ around 250 ms for starting up afterwards). This seems a bit excessive, so I just wanted to check. 

 

[Kenneth]

I can't see the current consumption and time scale from the picture you sent, but the time to execute a soft reset should be in the very few us range from soft reset is executed until CPU start to execute code from start or program, so if you measure ~730ms then it sounds to me that you must be measuring something else. Startup of an external 32kHz crystal can be some hundreds of ms, also erase flash pages can be roughly 100ms. 

Kenneth

[ned_zeppelin]

Thanks for the reply, makes sense that the soft reset is not the culprit. The large spike in the photo lasts for 730 ms (@ around 8 mA). Turns out that this is the bootloader validating the firmware. If I comment out the validation it takes about 700 ms less time. Not sure what the remaining ~250 ms before startup is, but some (or all) of it is probably startup of the external 32kHz crystal like you mentioned