Author: YongQ_16 Version: **
Translation - Japanese: パスワード保護を有効にしてフラッシュメモリをロックダウンする - KBA227884 - Community Translated (JA)
We are using Cypress S25FS512S flash. We need to set password to protect memory array to prevent user erasing/programing the memory array. Administrator can enter password to un-protect the memory to update software when necessary. How can I enable the Password Protection function?
Password Protection is part of the Cypress Advanced Sector Protection (ASP) feature. The ASP feature offers comprehensive solutions for protecting flash memory arrays. See AN98551 - Advanced Sector Protection (ASP) in Cypress Quad SPI, Octal SPI, and HyperFlash Device Fa... for more information about ASP.
This document provides tips on hands-on implementation of enabling ASP Password Protection mode, taking FS-S as an example. For other Cypress flash families, the steps are similar; commands and registers may not be the same. Refer to respective flash family datasheet for commands and registers details.
Enabling Password Protection function sets OTP registers; once set, it is not reversible. Do the following (if applicable to your application) before enabling the Password Protection function:
Do the following to enable the Password Protection function:
See the “Password Register” section in the FS512S datasheet .
2. After Password Program is complete, read the password (PASSRD E7h) to verify the correctness of the password programmed in Step 1.
3. Use the ASPP command (2Fh) or WRAR command (71h) to program the ASP Register (ASPR) to FFFBh (ASPR[2:1]=01b)
Example A: Sequence of commands to protect sectors and enable password protection to lock down a memory array:
Example B: Sequence of commands to unlock the protected sectors to update memory array: