51822 power on time

[aatt05]

everyone, i have a problem whit 51822. nRF5_SDK_12.3.0_d7731ad

i measure  time   from 51822 poweron to main . 

if i only softdevice and app code,  time is only  4-5ms only.       but if i burn softdevice and app and boot. time is 500ms from poweron to app main.

is it right?  from boot to app need so many time?

[Kenneth]

The startup time of the external 32kHz crystal is typically several hundred ms, so I expect your measurements to be correct.

You may use the internal 32KHz RC oscillator instead by changing NRF_CLOCK_LFCLKSRC to:

#define NRF_CLOCK_LFCLKSRC      {.source        = NRF_CLOCK_LF_SRC_RC,            \
                                 .rc_ctiv       = 32,                                \
                                 .rc_temp_ctiv  = 1,                                \
                                 .xtal_accuracy = NRF_CLOCK_LF_XTAL_ACCURACY_250_PPM}

[aatt05]

i am sorry. i do not know your mean. my boot code and app code use  

 #define NRF_CLOCK_LFCLKSRC      {.source        = NRF_CLOCK_LF_SRC_SYNTH,            \

if use NRF_CLOCK_LF_SRC_RC ,  will time is less? 

[Kenneth]

As long as you use that for both the bootloader and application yes.

Best regards,
Kenneth