M25P64
–
–
by setting the Status Register Write Disable
(SRWD) bit after driving Write Protect (W) Low
or by driving Write Protect (W) Low after
setting the Status Register Write Disable
(SRWD) bit.
The only way to exit the Hardware Protected Mode
(HPM) once entered is to pull Write Protect (W)
High.
If Write Protect (W) is permanently tied High, the
Hardware Protected Mode (HPM) can never be
activated, and only the Software Protected Mode
(SPM), using the Block Protect (BP2, BP1, BP0)
bits of the Status Register, can be used.
Figure 13. Write Status Register (WRSR) Instruction Sequence
S
0
C
Instruction
Status
Register In
7
High Impedance
Q
AI02282D
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15
D
6
5
4
3
2
1
0
MSB
19/38