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3669A–DFLASH–07/07

AT25DF321

The AT25DF321 also offers a sophisticated method for protecting individual sectors against

erroneous or malicious program and erase operations. By providing the ability to individually pro-

tect 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 applica-

tions where program code is patched or 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 capabili-

ties, the AT25DF321 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 since sectors do not have to be unprotected one-by-one prior

to initial programming.

Specifically designed for use in 3-volt systems, the AT25DF321 supports read, program, and

erase operations with a supply voltage range of 2.7V to 3.6V. No separate voltage is required for

programming and erasing.