Rainbow Electronics AT25DL161 - Manual (Page 2)

2 AT25DL161 [DATASHEET]
8795E–DFLASH–12/2012
1. Description
The AT25DL161 is a serial interface Flash memory device designed for use in a wide variety of high-volume, consumer-
based applications in which program code is shadowed from Flash memory into embedded or external RAM for
execution. The flexible erase architecture of the AT25DL161, with its erase granularity as small as 4KB, makes it ideal for
data storage as well, eliminating the need for additional data storage EEPROM devices.
The physical sectoring and the erase block sizes of the AT25DL161 have been optimized to meet the needs of today's
code and data storage applications. By optimizing the size of the physical sectors and erase blocks, the memory space
can be used much more efficiently. Because certain code modules and data storage segments must reside by
themselves in their own protected sectors, the wasted and unused memory space that occurs with large sectored and
large Block Erase Flash memory devices can be greatly reduced. This increased memory space efficiency allows
additional code routines and data storage segments to be added, while still maintaining the same overall device density.
The AT25DL161 also offers a sophisticated method for protecting individual sectors against erroneous or malicious
program and erase operations. By providing the ability to individually protect and unprotect sectors, a system can
unprotect a specific sector to modify its contents while keeping the remaining sectors of the memory array securely
protected. This is useful in applications where program code is patched, updated on a subroutine or module basis, or in
applications where data storage segments need to be modified without running the risk of errant modifications to the
program code segments. In addition to individual sector protection capabilities, the AT25DL161 incorporates Global
Protect and Global Unprotect features that allow the entire memory array to be either protected or unprotected all at
once. This reduces overhead during the manufacturing process because sectors do not have to be unprotected one by
one prior to initial programming.
To take code and data protection to the next level, the AT25DL161 incorporates a sector lockdown mechanism that
allows any combination of individual 64KB sectors to be locked down and become permanently read-only. This
addresses the need of certain secure applications that require portions of the Flash memory array to be permanently
protected against malicious attempts at altering program code, data modules, security information or
encryption/decryption algorithms, keys, and routines. The device also contains a specialized, OTP (One-Time
Programmable) security register, which can be used for unique device serialization, system-level Electronic Serial
Number (ESN) storage, locked key storage, or other purposes.
Specifically designed for use in 1.8V systems, the AT25DL161 supports read, program, and erase operations with a
supply voltage range of 1.65V to 1.95V. No separate voltage is required for programming and erasing.