S25FS-S datasheet(83/154 Pages) SPANSION

83 / 154 page

November 6, 2013 S25FS-S_00_04

S25FS-S Family

Da ta

Shee t

(Prelim i nar y )

9.4.5

Sector Protection States Summary

Each sector can be in one of the following protection states:

 Unlocked — The sector is unprotected and protection can be changed by a simple command. The

protection state defaults to unprotected when the device is shipped from Spansion.

 Dynamically Locked — A sector is protected and protection can be changed by a simple command. The

protection state is not saved across a power cycle or reset.

 Persistently Locked — A sector is protected and protection can only be changed if the PPB Lock bit is set

to 1. The protection state is non-volatile and saved across a power cycle or reset. Changing the protection

state requires programming and or erase of the PPB bits.

9.4.6

Persistent Protection Mode

The Persistent Protection method sets the PPB Lock bit to 1 during POR or hardware reset so that the PPB

bits are unprotected by a device hardware reset. Software reset does not affect the PPB Lock bit. The

PLBWR command can clear the PPB Lock bit to 0 to protect the PPB. There is no command to set the PPB

Lock bit therefore the PPB Lock bit will remain at 0 until the next power-off or hardware reset.

9.4.7

Password Protection Mode

Password Protection mode allows an even higher level of security than the Persistent Sector Protection

mode, by requiring a 64-bit password for unlocking the PPB Lock bit. In addition to this password

requirement, after power-up and hardware reset, the PPB Lock bit is cleared to 0 to ensure protection at

power-up. Successful execution of the Password Unlock command by entering the entire password sets the

PPB Lock bit to 1, allowing for sector PPB modifications.

Password Protection Notes:

 Once the Password is programmed and verified, the Password mode (ASPR[2]=0) must be set in order to

prevent reading the password.

 The Password Program Command is only capable of programming 0s. Programming a 1 after a cell is

programmed as a 0 results in the cell left as a 0 with no programming error set.

 The password is all 1s when shipped from Spansion. It is located in its own memory space and is

accessible through the use of the Password Program, Password Read, RDAR, and WRAR commands.

 All 64-bit password combinations are valid as a password.

 The Password mode, once programmed, prevents reading the 64-bit password and further password

programming. All further program and read commands to the password region are disabled and these

commands are ignored or return undefined data. There is no means to verify what the password is after the

Password Mode Lock bit is selected. Password verification is only allowed before selecting the Password

Protection mode.

 The Protection Mode Lock bits are not erasable.

Table 9.3 Sector Protection States

Protection Bit Values

Sector State

PPB Lock

PPB

DYB

Unprotected – PPB and DYB are changeable.

Protected – PPB and DYB are changeable.

Unprotected – PPB not changeable, DYB is changeable.

Protected – PPB not changeable, DYB is changeable.

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