S29GL128S SPANSION [SPANSION], S29GL128S Datasheet - Page 19

• Manufacturer Part Number: S29GL128S
• Manufacturer: SPANSION [SPANSION]

3.4
March 16, 2012 S29GL_128S_01GS_00_06
3.4.1
3.4.2
Sector Protection Methods
Write Protect Signal
ASP
If WP# = V
of any other ASP configuration. Whether it is the lowest or highest sector depends on the device ordering
option (model) selected. If WP# = V
but it may be protected by other aspects of ASP configuration. WP# has an internal pull-up; when
unconnected, WP# is at V
Advanced Sector Protection (ASP) is a set of independent hardware and software methods used to disable or
enable programming or erase operations, individually, in any or all sectors. This section describes the various
methods of protecting data stored in the memory array. An overview of these methods is shown in
Every main flash array sector has a non-volatile (PPB) and a volatile (DYB) protection bit associated with it.
When either bit is 0, the sector is protected from program and erase operations.
The PPB bits are protected from program and erase when the PPB Lock bit is 0. There are two methods for
managing the state of the PPB Lock bit, Persistent Protection and Password Protection.
The Persistent Protection method sets the PPB Lock to 1 during POR or Hardware Reset so that the PPB bits
are unprotected by a device reset. There is a command to clear the PPB Lock bit to 0 to protect the PPB.
3. N = Highest Address Sector.
Memory Array
IL
, the lowest or highest address sector is protected from program or erase operations independent
Sector N-2
Sector N-1
Sector N
Sector 0
Sector 1
Sector 2
3
D a t a
IH
.
Figure 3.1 Advanced Sector Protection Overview
GL-S MirrorBit
S h e e t
IH
0 = PPBs Locked
, the lowest or highest address sector is not protected by the WP# signal
4. 0 = Sector Protected,
5. PPBs set (programmed) individually,
1 = Sector Unprotected.
Password Method
but cleared (erased) collectively
64-bit Password
(One Time Protect)
Protection Bit
PPB Lock Bit
Persistent
®
(DQ2)
(PPB)
PPB N-2
PPB N-1
PPB N
PPB 0
PPB 1
PPB 2
Family
(One Time Programmable)
4,5
Lock Register
1 = PPBs Unlocked
1,2,3
Persistent Method
(DQ1)
6. 0 = Sector Protected,
7. Protect effective only if corresponding PPB
8. Volatile Bits: defaults to user choice upon
1 = Sector Unprotected.
is “1” (unprotected).
power-up (see ordering options).
1. Bit is volatile, and defaults to “1” on reset.
2. Programming to “0” locks all PPBs to their
3. Once programmed to “0”, requires hardware
current state.
reset to unlock.
Protection Bit
Dynamic
DYB N-2
DYB N-1
(DYB)
DYB N
DYB 0
DYB 1
DYB 2
6,7,8
Figure
3.1.
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