MX25L1635D
Table 7. ID Definitions
Command Type
MX25L1635D
Manufacturer ID Memory type
Memory Density
15
RDID (JEDEC ID)
RES
C2
24
Electronic ID
24
REMS/REMS2/
REMS4
Manufacturer ID
C2
Device ID
24
(19) Enter Secured OTP (ENSO)
The ENSO instruction is for entering the additional 512-bit secured OTP mode. The additional 512-bit secured OTP is
independentfrommainarray,whichmayusetostoreuniqueserialnumberforsystemidentifier.AfterenteringtheSecured
OTP mode, and then follow standard read or program, procedure to read out the data or update data. The Secured OTP
data cannot be updated again once it is lock-down.
The sequence of issuing ENSO instruction is: CS# goes low-> sending ENSO instruction to enter Secured OTP mode
-> CS# goes high.
PleasenotethatWRSR/WRSCURcommandsarenotacceptableduringtheaccessofsecureOTPregion,oncesecurity
OTP is lock down, only read related commands are valid.
(20) Exit Secured OTP (EXSO)
The EXSO instruction is for exiting the additional 512-bit secured OTP mode.
The sequence of issuing EXSO instruction is: CS# goes low-> sending EXSO instruction to exit Secured OTP mode->
CS# goes high.
(21)ReadSecurityRegister(RDSCUR)
TheRDSCURinstructionisforreadingthevalueofSecurityRegisterbits. TheReadSecurityRegistercanbereadatany
time (even in program/erase/write status register/write security register condition) and continuously.
ThesequenceofissuingRDSCURinstructionis:CS#goeslow->sendingRDSCURinstruction->SecurityRegisterdata
out on SO-> CS# goes high.
The definition of the Security Register bits is as below:
Secured OTP Indicator bit. The Secured OTP indicator bit shows the chip is locked by factory before ex- factory or not.
When it is "0", it indicates non- factory lock; "1" indicates factory- lock.
Lock-downSecuredOTP(LDSO)bit.BywritingWRSCURinstruction,theLDSObitmaybesetto"1" forcustomerlock-
down purpose. However, once the bit is set to "1" (lock-down), the LDSO bit and the 512-bit Secured OTP area cannot
be update any more. While it is in 512-bit secured OTP mode, main array access is not allowed.
ContinuouslyProgramMode(CPmode)bit. TheContinuouslyProgramModebitindicatesthestatusofCPmode, "0"
indicates not in CP mode; "1" indicates in CP mode.
P/N:PM1374
REV. 1.5, OCT. 01, 2008
23
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