4.2.5.4 Set Lock Bit and User Unlock Commands
There is a user page lock bit to lock the page for writing. The Control Register PAGE_LOCK_SET[0] is used to set the user lock bit of the page. Refer to PAGE_LOCK_SET register in Table 4-20 for more information. If PAGE_LOCK_SET[0] == 1, then nv_s_page_lock_set will be asserted when submitting the address for Program.
To program a page, the User Unlock command must be submitted before submitting ProgramAd or ProgramADS.