AM29PDLI27H SPANSION [SPANSION], AM29PDLI27H Datasheet - Page 31

• Manufacturer Part Number: AM29PDLI27H
• Description: 128 Megabit (8 M x 16-Bit) CMOS 3.0 Volt-only, Page Mode Simultaneous Read/Write Flash Memory with Enhanced VersatileIO Control
• Manufacturer: SPANSION [SPANSION]

Temporary Sector Unprotect
This feature allows temporary unprotection of previ-
ously protected sectors to change data in-system. The
Sector Unprotect mode is activated by setting the RE-
SET# pin to
sectors can be programmed or erased by selecting the
sector addresses. Once V
SET# pin, all the previously protected sectors are
protected again. Figure 2 shows the algorithm, and
Figure 22 shows the timing diagrams, for this feature.
While PPB lock is set, the device cannot enter the
Temporary Sector Unprotection Mode.
SecSi™ (Secured Silicon) Sector
Flash Memory Region
The SecSi (Secured Silicon) Sector feature provides a
Flash memory region that enables permanent part
identification through an Electronic Serial Number
(ESN) The 128-word SecSi sector is divided into 64
factory-lockable words that can be programmed and
locked by the customer. The SecSi sector is located at
addresses 000000h-00007Fh in both Persistent Pro-
tection mode and Password Protection mode. It uses
June 30, 2003
Notes:
1. All protected sectors unprotected (If WP#/ACC = V
2. All previously protected sectors are protected once
Figure 2. Temporary Sector Unprotect Operation
sectors 0, 1, 268, 269 will remain protected).
again.
V
ID
. During this mode, formerly protected
Unprotect Completed
Program Operations
Temporary Sector
Perform Erase or
RESET# = V
RESET# = V
(Note 1)
(Note 2)
ID
START
is removed from the RE-
A D V A N C E
ID
IH
Am29PDL127H
IL
,
I N F O R M A T I O N
i nd ica tor b its ( D Q6 , D Q7 ) to i nd ica te th e fac-
tory-locked and customer-locked status of the part.
The system accesses the SecSi Sector through a
command sequence (see “Enter SecSi™ Sector/Exit
SecSi Sector Command Sequence”). After the system
has written the Enter SecSi Sector command se-
quence, it may read the SecSi Sector by using the ad-
dresses normally occupied by the boot sectors. This
mode of operation continues until the system issues
the Exit SecSi Sector command sequence, or until
power is removed from the device. On power-up, or
following a hardware reset, the device reverts to send-
ing commands to the normal address space. Note that
the ACC function and unlock bypass modes are not
available when the SecSi Sector is enabled.
Factory-Locked Area (64 words)
T h e f a c t o r y - l o c k e d a r e a o f t h e S e c S i S e c t o r
(000000h-00003Fh) is locked when the part is
shipped, whether or not the area was programmed at
the factory. The SecSi Sector Factory-locked Indicator
Bit (DQ7) is permanently set to a “1”. AMD offers the
ExpressFlash service to program the factory-locked
area with a random ESN, a customer-defined code, or
any combination of the two. Because only AMD can
program and protect the factory-locked area, this
method ensures the security of the ESN once the
product is shipped to the field. Contact an AMD repre-
sentative for details on using AMD’s ExpressFlash
service.
Customer-Lockable Area (64 words)
The customer-lockable area of the SecSi Sector
(000040h-00007Eh) is shipped unprotected, which al-
lows the customer to program and optionally lock the
area as appropriate for the application. The SecSi
Sector Customer-locked Indicator Bit (DQ6) is shipped
as “0” and can be permanently locked to “1” by issuing
the SecSi Protection Bit Program Command. The
SecSi Sector can be read any number of times, but
can be programmed and locked only once. Note that
the accelerated programming (ACC) and unlock by-
pass functions are not available when programming
the SecSi Sector.
The Customer-lockable SecSi Sector area can be pro-
tected using one of the following procedures:
Write the three-cycle Enter SecSi Sector Region
command sequence, and then follow the in-system
sector protect algorithm as shown in
cept that RESET# may be at either V
allows in-system protection of the SecSi Sector Re-
gion without raising any device pin to a high voltage.
Note that this method is only applicable to the SecSi
Sector.
To verify the protect/unprotect status of the SecSi
Sector, follow the algorithm shown in
IH
Figure
Figure
or V
ID
3.
1, ex-
. This
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