ES29LV160F Datasheet, PDF (63/71 Pages) Excel Semiconductor Inc. – 16 Megabit (2 M x 8-Bit/1 M x 16-Bit) CMOS 3.0 Volt-only Boot Sector Flash Memory

ES29LV160F
Excel Semiconductor Inc.
A5. Security Sector (256 bytes)
The security sector of the ES29LV160F device provides an extra flash memory space that enables
permanent part identification through an Electronic Serial Number (ESN). The security sector uses
a security lock-Indicator Bit (DQ7) to indicate whether or not the security sector is locked when
shipped from the factory. This bit is permanently set at the factory and cannot be changed, which
prevents cloning a factory locked part. This ensures the security of the ESN once the product is
shipped to the field. Note that the ES29LV160F has a security sector size of 256 bytes.
Security Lock-Indicator Bit (DQ7)
In the device, the security sector can be provided in either factory locked version or customer
lockable version. The factory-locked version is always protected when shipped from the factory,
and has the security lock-Indicator Bit permanently set to a “1”.
The customer-lockable version is shipped with the security sector unprotected, allowing customers
to utilize the sector in any manner they choose. The customer-lockable version has the security
lock-Indicator Bit permanently set to a “0”. Thus, the security lock-Indicator Bit prevents customer-
lockable devices from being used to replace devices
that are factory locked. The security customer indicator Bit(DQ6) is permanently set to “1” if the
part has been customer locked, permanently set to “0” if the part has been factory locked, and is
“0” if customer lockable.
Access to the Security Sector
The security sector can be accessed through a command sequence: Enter security and Exit
security sector commands. After the system has written the Enter security sector command
sequence, it may read the security sector by using the addresses normally occupied by the boot
sectors.
This mode of operation continues until the system issues the Exit security sector command
sequence, or until power is removed from the device. On power-up, or following a hardware reset,
the device returns to read mode in which the normal boot sectors can be accessed, instead of the
security sector.
Factory-Locked Device
In a factory-locked device, the security sector is protected when the device is shipped from the
factory. The security sector cannot be modified in any way. So, customer own codes like ESN
( Electronic Serial Number ) can be safely stored in this factory-locked security sector arera.
The device is available preprogrammed with one of the following:
Rev.0A (Dec 12, 2007) 63