EN25LF10
The status and control bits of the Status Register are as follows:
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 both 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) Sector Erase (SE) and , Block Erase (BE), instructions. The Block Protect (BP2, BP1,
BP0) bits can be written provided that the Hardware Protected mode has not been set. The Chip Erase
(CE) instruction is executed if, and only if, both Block Protect (BP2, BP1, BP0) bits are 0.
Reserved bit. Status register bit locations 5 and 6 are reserved for future use. Current devices will read
0 for these bit locations. It is recommended to mask out the reserved bit when testing the Status
Register. Doing this will ensure compatibility with future devices.
SRP bit / OTP_LOCK bit. The Status Register Protect (SRP) bit is operated in conjunction with the
Write Protect (WP#) signal. The Status Register Write Protect (SRP) bit and Write Protect (WP#) signal
allow the device to be put in the Hardware Protected mode (when the Status Register Protect (SRP) bit
is set to 1, and Write Protect (WP#) is driven Low). In this mode, the non-volatile bits of the Status
Register (SRP, BP2, BP1, BP0) become read-only bits and the Write Status Register (WRSR)
instruction is no longer accepted for execution.
In OTP mode, this bit is served as OTP_LOCK bit, user can read/program/erase OTP sector as normal
sector while OTP_LOCK value is equal 0, after OTP_LOCK is programmed with 1 by WRSR command,
the OTP sector is protected from program and erase operation. The OTP_LOCK bit can only be
programmed once.
Note : In OTP mode, the WRSR command will ignore any input data and program OTP_LOCK bit to 1, user must
clear the protect bits before enter OTP mode and program the OTP code, then execute WRSR command to lock
the OTP sector before leaving OTP mode.
Write Status Register (WRSR) (01h)
The Write Status Register (WRSR) instruction allows new values to be written to the Status Register.
Before it can be accepted, a Write Enable (WREN) instruction must previously have been executed.
After the Write Enable (WREN) instruction has been decoded and executed, the device sets the Write
Enable Latch (WEL).
The Write Status Register (WRSR) instruction is entered by driving Chip Select (CS#) Low, followed by
the instruction code and the data byte on Serial Data Input (DI).
The instruction sequence is shown in Figure 8. The Write Status Register (WRSR) instruction has no
effect on S6, S5, S1 and S0 of the Status Register. S6 and S5 are always read as 0. Chip Select (CS#)
must be driven High after the eighth bit of the data byte has been latched in. If not, the Write Status
Register (WRSR) instruction is not executed. As soon as Chip Select (CS#) is driven High, the self-
timed Write Status Register cycle (whose duration is t ) is initiated. While the Write Status Register
W
cycle is in progress, the Status Register may still be read to check the value of the Write In Progress
(WIP) bit. The Write In Progress (WIP) bit is 1 during the self-timed Write Status Register cycle, and is
0 when it is completed. When the cycle is completed, the Write Enable Latch (WEL) is reset.
The Write Status Register (WRSR) instruction allows the user to change the values of the Block Protect
(BP2, BP1, BP0) bits, to define the size of the area that is to be treated as read-only, as defined in
Table 3.. The Write Status Register (WRSR) instruction also allows the user to set or reset the Status
Register Protect (SRP) bit in accordance with the Write Protect (WP#) signal. The Status Register
Protect (SRP) bit and Write Protect (WP#) signal allow the device to be put in the Hardware Protected
This Data Sheet may be revised by subsequent versions
or modifications due to changes in technical specifications.
©2004 Eon Silicon Solution, Inc.,
www.eonssi.com
12
Rev. E, Issue Date: 2011/05/19
EON [ EON SILICON SOLUTION INC. ]
