Nordic51822AA hrs project can not enter main SDK12.3

Question

Hi，
First,i want to develop my project via SDK12.3 hrs project. I download the SD and app in hrs project in SDK12.3 via Keil ,but it does not work. I enter debug mode and find it can not enter main function(See Picture_1).
 Picture_1.png 
 Second,I download the SD and app in experimental_ble_app_blinky project in SDK12.3 via Keil , it can enter main function.I change the clock to NRF_CLOCK_LF_SRC_SYNTH, it works well.(See Picture_2).
 Picture_2.png 
 All settings are default setting in the two projects. I doubt the ram(Nordic 51822AA 16K RAM) is not enough in hrs project. what can i do to solve the problem? I want to use hrs project as the reference of my own projcet ,and use Nordic 51822AA 16K RAM to develop.It is better not to replace any of them. 
 regards,
alivexiaoluo.

bjorn-spockeli · Accepted Answer

Hi alivexiaoluo, 
 if you're using a custom nRF51822 module that does not have the optional 32kHz crystal, then you need to set the internal RC oscillator as the LFCLK source, i.e. you need to modify the NRF_CLOCK_LFCLKSRC in the pca10040.h or custom_board.h to the following 
 #define NRF_CLOCK_LFCLKSRC {.source = NRF_CLOCK_LF_SRC_RC, \

 .rc_ctiv = 16, \

 .rc_temp_ctiv = 2, \

 .xtal_accuracy = NRF_CLOCK_LF_XTAL_ACCURACY_250_PPM }
 
 Secondly you need to modify the RAM settings so that it takes into account the 16kB of RAM, i.e. 
 IRAM1 Start: 0x20001FE8 Size: 0x2018
 
 Best regards 
 Bjørn