6.4.1 Block Write-Protect Function
The
WRSR instruction allows the user to configure one of four memory array
write-protection modes by setting the Block Write-Protect bits (BP1, BP0). The available
protection levels are:- No protection applied to the memory array
- The upper quarter (¼) of the address range is write-protected, making the highest address range read-only
- The upper half (½) of the address range is write-protected, making the highest address range read-only
- The entire memory array is write-protected, making all addresses read-only
The Block Write-Protect levels and their corresponding STATUS register control bits are
listed in Table 6-4.
| Level | STATUS Register Bits | Write-Protected/Read‑Only Address Range | |||
|---|---|---|---|---|---|
| BP1 | BP0 | AT25010B | AT25020B | AT25040B | |
| 0 | 0 | 0 | None | None | None |
| 1 (1/4) | 0 | 1 | 60h-7Fh | C0h-FFh | 180h-1FFh |
| 2 (1/2) | 1 | 0 | 40h-7Fh | 80h-FFh | 100h-1FFh |
| 3 (All) | 1 | 1 | 00h-7Fh | 00h-FFh | 000h-1FFh |