s130 sdkv12 DFU secure bootloader example in nrf51822 chip

Question

when I run the secure bootloader example in nrf51422 development board, the code is working fine. I am able to load the packet through nrf toolbox app. But the same code when I run in my custom 51822 board (PTR5518A), the bootloader code is not running and not advertising. I even tried to change the RAM and flash memory size. 
 FLASH (rx) : ORIGIN = 0x3AC00, LENGTH = 0x5000,
RAM (rwx) : ORIGIN = 0x20002C00, LENGTH = 0x1000,
NOINIT (rwx) : ORIGIN = 0x20003F80, LENGTH = 0x80,
BOOTLOADER_SETTINGS (rw) : ORIGIN = 0x0003FC00, LENGTH = 0x0400,
BOOTLOADER_SETTINGS (rw) : ORIGIN = 0x0003FC00, LENGTH = 0x0400,
UICR_BOOTLOADER (r) : ORIGIN = 0x10001014, LENGTH = 0x04.
 
 These are the current memory settings. With this same settings things are working with the development board (nrf51422) but not in 51822. What changes are required to make it work on nrf51822 ?

bjorn-spockeli · Accepted Answer

Then you need to change the NRF_CLOCK_LFCLKSRC passed to the SOFTDEVICE_HANDLER_APPSH_INIT macro in ble_stack_init() (in the default example its defined in pca10028.h ) to the following 
 #define NRF_CLOCK_LFCLKSRC {.source = NRF_CLOCK_LF_SRC_RC, \
 .rc_ctiv = 16, \
 .rc_temp_ctiv = 2, \
 .xtal_accuracy = 0}