failing while doing the flashwrite example

[pallavi]

hello, i am doing flash read and write in nrf51.for which i have used the C:\nRF5_SDK_12.2.0_f012efa\examples\peripheral\flashwrite\pca10028\blank\arm4 this exampl. but while doing this my nrf51-DK borad stopped response and it showing errors while programming

i have just executed this code , void main() { uint32_t * addr; uint8_t patwr; uint8_t patrd; uint8_t patold; uint32_t i; uint32_t pg_size; uint32_t pg_num;

uint32_t err_code;

err_code = NRF_LOG_INIT(NULL);
APP_ERROR_CHECK(err_code);

NRF_LOG_INFO("Flashwrite example\r\n");
patold  = 0;
pg_size = NRF_FICR->CODEPAGESIZE;
pg_num  = NRF_FICR->CODESIZE - 1;  // Use last page in flash

while (true)
{
    // Start address:
    addr = (uint32_t *)(pg_size * pg_num);
    // Erase page:
    flash_page_erase(addr);
    i = 0;
    NRF_LOG_INFO("'%p' is the address",(unsigned int)addr);
		  NRF_LOG_INFO("'%d' is the page size",pg_size);
			NRF_LOG_INFO("'%d' is the page number",pg_num);

}} after that it shows the errors can not write on address 0x4000..

can anyone please tell me from which address i have to write data on the flash the default starting page mentioned is 255 and the comment is given in example use last page. i want to ask what pages i can use for saving the data on the flash?

[FormerMember]

Do you mean that you cannot write to address 0x40000, if so, that's because of the amount of flash on the nRF51822, 256 kB.

256 kB = 0x40000 bytes

You can save data in any flash page, as long as it is not used by anything else.

[FormerMember]

Yes, the flash is shared between the source code, so the 256 kB is the total amount of flash for both the source code and "application stored data". The source code starts (by default) at address 0x00, and is written continuously from there. After the "end of" the source code, the application can use the rest.