about nrf52832 write flash by jlink

[Liny]

hi ，i want write flash by jlink，eg：write val 0xaaffffff to addr 0x76000, only write 4byte.

but when i write, err "flash not erase" occurred，

I don't want to erase this flash because there are other data on this page.

So I want to ask if there is a way to rewrite only one byte of the flash of this page through JLINK without erasing the whole page of flash.

[qwertynoon]

You must to erase page before flashing. While flash nrf52 can set 1 to 0 and can not to set 0 to 1. thats why first you erase page (erase process set 0 to 1) and then you can flash your data

[Hung Bui]

Hi,

Just as Vasiliy said. You need to erase the flash area before you write to it. 

If you want to keep the content of the flash page, you would need to read the content out, modify what  you want to change and then erase and write the new content back. 

If you only change from 1 to 0 on the bit, and don't want to erase you can try using nrfjprog --memwr . This tool won't require the whole flash page to be erased to write.