MX29LV320MB Macronix International, MX29LV320MB Datasheet - Page 15

• Manufacturer Part Number: MX29LV320MB
• Description: 32M-BIT [4M x 8/2M x 16] SINGLE VOLTAGE 3V ONLY FLASH MEMORY
• Manufacturer: Macronix International

Which the identified sector is protected, the device will
output 01H. Which the identified sector is not protect, the
device will output 00H.
DATA PROTECTION
The MX29LV320MT/B is designed to offer protection
against accidental erasure or programming caused by
spurious system level signals that may exist during power
transition. During power up the device automatically re-
sets the state machine in the Read mode. In addition,
with its control register architecture, alteration of the
memory contents only occurs after successful comple-
tion of specific command sequences. The device also
incorporates several features to prevent inadvertent write
cycles resulting from VCC power-up and power-down tran-
sition or system noise.
SECURED SILICON SECTOR
The MX29LV320MT/B features a OTP memory region
where the system may access through a command se-
quence to create a permanent part identification as so
called Electronic Serial Number (ESN) in the device.
Once this region is programmed, any further modification
on the region is impossible. The secured silicon sector is
a 128 words in length, and uses a Secured Silicon Sector
Indicator Bit (Q7) to indicate whether or not the Secured
Silicon Sector is locked when shipped from the factory.
This bit is permanently set at the factory and cannot be
changed, which prevent duplication of a factory locked
part. This ensures the security of the ESN once the prod-
uct is shipped to the field.
The MX29LV320MT/B offers the device with Secured
Silicon Sector either factory locked or customer lockable.
The factory-locked version is always protected when
shipped from the factory , and has the Secured Silicon
Sector Indicator Bit permanently set to a "1". The cus-
tomer-lockable version is shipped with the Secured Sili-
con Sector unprotected, allowing customers to utilize that
sector in any form they prefer. The customer-lockable ver-
sion has the secured sector Indicator Bit permanently
set to a "0". Therefore, the Secured Silicon Sector Indi-
cator Bit prevents customer, lockable device from being
used to replace devices that are factory locked.
The system access the Secured Silicon Sector through
a command sequence (refer to "Enter Secured Silicon/
Exit Secured Silicon Sector command Sequence). After
P/N:PM1129
15
the system has written the Enter Secured Silicon Sector
command sequence, it may read the Secured Silicon
Sector by using the address normally occupied by the
first sector SA0. Once entry the Secured Silicon Sector
the operation of boot sectors is disabled but the operation
of main sectors is as normally. This mode of operation
continues until the system issues the Exit Secured Sili-
con Sector command sequence, or until power is removed
from the device. On power-up, or following a hardware
reset, the device reverts to sending command to sector
SA0.
FACTORY LOCKED:Secured Silicon Sector
Programmed and Protected At the Factory
In device with an ESN, the Secured Silicon Sector is
protected when the device is shipped from the factory.
The Secured Silicon Sector cannot be modified in any
way. A factory locked device has an 8-word random ESN
at address 000000h-000007h.
CUSTOMER LOCKABLE:Secured Silicon Sec-
tor NOT Programmed or Protected At the Fac-
tory
As an alternative to the factory-locked version, the de-
vice may be ordered such that the customer may pro-
gram and protect the 128-word Secured Silicon Sector.
Programming and protecting the Secured Silicon Sector
must be used with caution since, once protected, there
is no procedure available for unprotected the Secured
Silicon Sector area and none of the bits in the Secured
Silicon Sector memory space can be modified in any way.
The Secured Silicon Sector area can be protected using
one of the following procedures:
Write the three-cycle Enter Secured Silicon Sector Re-
gion command sequence, and then follow the in-system
sector protect algorithm as shown in Figure 15, except
that RESET# may be at either VIH or VID. This allows in-
MX29LV320MT/B
Secured Silicon
Sector address
000000h-000007h
000008h-00007Fh
ESN factory
Unavailable
locked
range
ESN
REV. 1.1 , JUL. 14, 2005
Determined by
www.DataSheet4U.com
Customer
Customer
lockable