nrf51288-DK storage

@Robin

The 181 value indicates the number of writes before an erase must be performed. One then could write all 256 32 bit words, one by one with an intermediate erase.

Oh I got the numbers wrong. It looks like block is 512 bytes long, not 1024. So I can write it in 128 steps. This now makes sense. So I have 53 spare writes to rewrite some 32bit words second time.

@Vlad
Looks like nrf51822 has 20K writes limit per page and there is no such strange write limit for whole blocks. It says that each individual word can be written two times. In fact when checking documentation only nrf52832 has this. E.g. the 52811 or the newest 52840 has only limit per individual word like nrf51822 .

So as I understand it with nrf51822 you can write each 32bit word twice, then you need to erase whole page and this page erase counts as one from 20K per page.