EN25F40A
Active Power, Stand-by Power and Deep Power-Down Modes
When Chip Select (CS#) is Low, the device is enabled, and in the Active Power mode. When Chip
Select (CS#) is High, the device is disabled, but could remain in the Active Power mode until all internal
cycles have completed (Program, Erase, and Write Status Register). The device then goes into the
Stand-by Power mode. The device consumption drops to ICC1
.
The Deep Power-down mode is entered when the specific instruction (the Enter Deep Power-down
Mode (DP) instruction) is executed. The device consumption drops further to ICC2. The device remains in
this mode until another specific instruction (the Release from Deep Power-down Mode and Read Device
ID (RDI) instruction) is executed.
All other instructions are ignored while the device is in the Deep Power-down mode. This can be used
as an extra software protection mechanism, when the device is not in active use, to protect the device
from inadvertent Write, Program or Erase instructions.
Status Register
The Status Register contains a number of status and control bits that can be read or set (as appropriate)
by specific instructions.
WIP bit. The Write In Progress (WIP) bit indicates whether the memory is busy with a Write Status
Register, Program or Erase cycle.
WEL bit. The Write Enable Latch (WEL) bit indicates the status of the internal Write Enable Latch.
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.
WHDIS bit. The WP# and Hold# Disable bit (WHDIS bit), non-volatile bit, it indicates the WP# and
HOLD# are enabled or not. When it is “0” (factory default), the WP# and HOLD# are enabled. On the
other hand, while WHDIS bit is “1”, the WP# and HOLD# are disabled. No matter WHDIS is “0” or
“1”, the system can executes Quad Input/Output FAST_READ (EBh), Quad Input Page Program (32h)
or EQPI (38h) command directly. User can use Flash Programmer to set WHDIS bit as “1” and then
the host system can let WP# and HOLD# keep floating in 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 Protect (SRP) bit and Write Protect (WP#) signal allow the
device to be put in the Hardware Protected mode. In this mode, the non-volatile bits of the Status
Register (SRP, BP3, BP2, BP1, BP0) become read-only bits.
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, user must clear the protect bits before entering OTP mode and program the OTP
code, then execute WRSR command to set OTP_LOCK = “1” to lock the OTP sector before leaving
OTP mode.
This Data Sheet may be revised by subsequent versions
or modifications due to changes in technical specifications.
Elite Semiconductor Memory Technology Inc.
9
Rev. D, Issue Date: 2017/02/13
ESMT [ ELITE SEMICONDUCTOR MEMORY TECHNOLOGY INC. ]
