EN25Q64 Datasheet, PDF (21/60 Pages) Eon Silicon Solution Inc. – 64 Megabit Serial Flash Memory with 4Kbyte Uniform Sector

EN25Q64
Table 6. Status Register Bit Locations
S7
S6
S5
S4
S3
S2
S1
SRP
Status
Register
Protect
OTP_LOCK
bit
(note 1)
WPDIS
(WP# disable)
BP3
(Block
Protected bits)
BP2
(Block
Protected bits)
BP1
BP0
(Block
(Block
Protected bits) Protected bits)
WEL
(Write Enable
Latch)
S0
WIP
(Write In
Progress bit)
(Note 3)
1 = status 1 = OTP
register write sector is
disable protected
1 = WP#
disable
0 = WP#
enable
(note 2)
(note 2)
(note 2)
(note 2)
1 = write
enable
0 = not write
enable
1 = write
operation
0 = not in write
operation
Non-volatile bit
Non-volatile bit Non-volatile bit. Non-volatile bit Non-volatile bit Non-volatile bit volatile bit
volatile bit
Note
1. In OTP mode, SRP bit is served as OTP_LOCK bit.
2. See the table “Protected Area Sizes Sector Organization”.
3. When executed the (RDSR) (05h) command, the WIP (S0) value is the same as WIP (S7) in table 7.
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.
BP3, BP2, BP1, BP0 bits. The Block Protect (BP3, 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 (BP3,
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
(BP3, 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, all Block Protect (BP3, BP2, BP1, BP0) bits
are 0.
WPDIS bit. The Write Protect disable (WPDIS) bit, non-volatile bit, when it is reset to “0” (factory
default) to enable WP# function or is set to “1” to disable WP# function (can be floating during SPI
mode.)
SRP bit / OTP_LOCK bit. The Status Register Protect (SRP) bit operates 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, BP3, 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 serves as OTP_LOCK bit, user can read/program/erase OTP sector as normal
sector while OTP_LOCK bit value is equal 0, after OTP_LOCK bit 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.
This Data Sheet may be revised by subsequent versions
21
or modifications due to changes in technical specifications.
©2004 Eon Silicon Solution, Inc.,
Rev. E, Issue Date: 2009/10/19
www.eonssi.com