EN25T16A Datasheet, PDF (7/35 Pages) Eon Silicon Solution Inc. – 16 Megabit Uniform Sector, Serial Flash Memory

EN25T16A
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.
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.
Mode1, Mode0 bits. Default value is SPI mode (00), user can change this value by change mode
commands to change the interface mode. This device also support SP2 mode (01).
SP2 mode : command/address/data all transmitting with 2 bits
SRP bit / OTP_LOCK bit The Status Register Protect (SRP) bit is operated 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, BP2, BP1, BP0) become read-only bits.
In OTP mode, this bit is served 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.
Write Protection
Applications that use non-volatile memory must take into consideration the possibility of noise and other
adverse system conditions that may compromise data integrity. To address this concern the EN25T16A
provides the following data protection mechanisms:
z Power-On Reset and an internal timer (tPUW) can provide protection against inadvertent changes
while the power supply is outside the operating specification.
z Program, Erase and Write Status Register instructions are checked that they consist of a number
of clock pulses that is a multiple of eight, before they are accepted for execution.
z All instructions that modify data must be preceded by a Write Enable (WREN) instruction to set
the Write Enable Latch (WEL) bit . This bit is returned to its reset state by the following events:
– Power-up
– Write Disable (WRDI) instruction completion or Write Status Register (WRSR) instruction
completion or Page Program (PP) instruction completion or Sector Erase (SE)instruction
completion or Block Erase (BE) instruction completion or Chip Erase (CE) instruction
completion
z The Block Protect (BP2, BP1, BP0) bits allow part of the memory to be configured as read-only.
This is the Software Protected Mode (SPM).
z The Write Protect (WP#) signal allows the Block Protect (BP2, BP1, BP0) bits and Status Register
Protect (SRP) bit to be protected. This is the Hardware Protected Mode (HPM).
z In addition to the low power consumption feature, the Deep Power-down mode offers extra
software protection from inadvertent Write, Program and Erase instructions, as all instructions are
ignored except one particular instruction (the Release from Deep Power-down instruction).
This Data Sheet may be revised by subsequent versions
7
or modifications due to changes in technical specifications.
©2004 Eon Silicon Solution, Inc.,
Rev. C, Issue Date: 2011/04/15
www.eonssi.com