halt Flash write

Question

Dear everyone: 
 Can you tell me Using built-in flash and use restrictions, 
 because it halt at ble_flash_page_write() function.

Håkon Alseth · Accepted Answer

If you are trying to write to an address which the softdevice uses, you will most likely end up in the hard-fault handler, as this is a restricted address area.
If you write to the top of the flash, this should not be an issue.
How much data are you writing to flash?
Are you doing this while in a BLE connection? 
 If you are depending on writing data to the flash while in a connection, you should enable radio notification which will give you a "safe" window of up to 5.5 ms for you to store into flash.
Most examples use this to store bonding information (ex: ble_app_cscs, ble_app_gls etc)