Instructions
M25PX16
Table 7.
Status Register format
b7
b0
SRWD
0
TB
BP2
BP1
BP0
WEL
WIP
Status Register Write Protect
Top/Bottom bit
Block Protect bits
Write Enable Latch bit
Write In Progress bit
The status and control bits of the Status Register are as follows:
6.4.1
6.4.2
6.4.3
WIP bit
The Write In Progress (WIP) bit indicates whether the memory is busy with a Write Status
Register, Program or Erase cycle. When set to 1, such a cycle is in progress, when reset to
0 no such cycle is in progress.
WEL bit
The Write Enable Latch (WEL) bit indicates the status of the internal Write Enable Latch.
When set to 1 the internal Write Enable Latch is set, when set to 0 the internal Write Enable
Latch is reset and no Write Status Register, Program or Erase instruction is accepted.
BP2, BP1, BP0 bits
The Block Protect (BP2, BP1, BP0) bits are non-volatile. They define the size of the area to
be software protected against Program and Erase instructions. These bits are written with
the Write Status Register (WRSR) instruction. When one or more of the Block Protect (BP2,
BP1, BP0) bits is set to 1, the relevant memory area (as defined in Table 3) becomes
protected against Page Program (PP) and Sector Erase (SE) instructions. The Block Protect
(BP2, BP1, BP0) bits can be written provided that the Hardware Protected mode has not
been set. The Bulk Erase (BE) instruction is executed if, and only if, all Block Protect (BP2,
BP1, BP0) bits are 0.
6.4.4
TB bit
The Top/Bottom (TB) bit is non-volatile. It can be set and reset with the Write Status Register
(WRSR) instruction provided that the Write Enable (WREN) instruction has been issued.
The Top/Bottom (TB) bit is used in conjunction with the Block Protect (BP0, BP1, BP2) bits
to determine if the protected area defined by the Block Protect bits starts from the top or the
bottom of the memory array:
When TB is reset to ‘0’ (default value), the area protected by the Block Protect bits
starts from the top of the memory array (see Table 3: Protected area sizes)
When TB is set to ‘1’, the area protected by the Block Protect bits starts from the
bottom of the memory array (see Table 3: Protected area sizes)
The TB bit cannot be written when the SRWD bit is set to ‘1’ and the W pin is driven Low.
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