NRF51822 Flash write ,lead to undesirable value

Question

I have Inited the pstorage 
 err_code = pstorage_init();
 APP_ERROR_CHECK(err_code);
 
 Here PSTORAGE_NUM_OF_PAGES=2(1page for bonding ,1page for my application use ) .and register my page 
 param.block_size = sizeof (m_sys_data_store) ;//36bytes
	param.block_count = 1;
	param.cb = sys_updata_storage_cb_handler;
	
	err_code = pstorage_register(&param, &mp_sys_info_flash);
 
 here param.block_size=36 bytes .Mine flash operation like this 
 err_code=sys_info_clear_from_flash();//==pstorage_clear(&mp_sys_info_flash, sizeof(m_sys_data_store));
	if (err_code != NRF_SUCCESS)
	{
 return ;
	}
	for(err_code=0;err_code<4800000;err_code++){;}//wait for flash operation finish
	
	m_sys_data_store._flag=0xaabbccdd;

	err_code=sys_info_updata_to_flash(&m_sys_data_store);
	if (err_code != NRF_SUCCESS)
	{
 return ;
	}
	for(err_code=0;err_code<4800000;err_code++){;}
 
 sometime the write result is 0xaabbccdd ,but somtime is 0xffffffff , 0x00000000 or others.
the function sys_info_updata_to_flash show as follow: 
 uint32_t sys_info_updata_to_flash(sys_info_store_block_t * sys_data) 
{
 uint32_t err_code;
 pstorage_handle_t dest_block;
	
 
 // Get block pointer from base
	err_code = pstorage_block_identifier_get(&mp_sys_info_flash,0,&dest_block);
	if (err_code != NRF_SUCCESS)
	{
 return err_code;
	}
	err_code=sizeof(m_sys_data_store);//test
	err_code = pstorage_store(&dest_block,(uint8_t *)sys_data,sizeof(m_sys_data_store),0);
	if (err_code != NRF_SUCCESS)
	{
 return err_code;
	}
	return NRF_SUCCESS;
}
 
 The porject base on SDK9.0,S130.Why does the flash operation be so complex?I have no ideal to solute it,help me please.

Artucas · Accepted Answer

If you want to update the contents of flash memory, you can't use pstorage_store(); for every time you want to write something to flash. That is valid only for the first time. If you want to update flash contents to which you have already written, you should use pstorage_update(); instead. Using pstorage_store(); on a flash region which was already written might cause unpredictable results. I have recently also tried to run pstorage module and i got everything working correct, but i did it on S110 V8. You can check it here pstorage_update callback

NRF51822 Flash write ,lead to undesirable value

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