s29jl064h Meet Spansion Inc., s29jl064h Datasheet - Page 26

• Manufacturer Part Number: s29jl064h
• Description: 64 Megabits 8 M X 8-bits / 4 M X 16-bits
• Manufacturer: Meet Spansion Inc.

8.13
26
8.13.1
8.13.2
Secured Silicon Sector Flash Memory Region
Factory Locked: Secured Silicon Sector Programmed and Protected At the
Factory
Customer Lockable: Secured Silicon Sector NOT Programmed or Protected
At the Factory
The Secured Silicon Sector feature provides a Flash memory region that enables permanent part
identification through an Electronic Serial Number (ESN). The Secured Silicon Sector is 256 bytes in length,
and uses a Secured Silicon Sector Indicator Bit (DQ7) to indicate whether or not the Secured Silicon Sector is
locked when shipped from the factory. This bit is permanently set at the factory and cannot be changed,
which prevents cloning of a factory locked part. This ensures the security of the ESN once the product is
shipped to the field.
The product is available with the Secured Silicon Sector either factory locked or customer lockable. The
factory-locked version is always protected when shipped from the factory, and has the Secured Silicon Sector
Indicator Bit permanently set to a 1. The customer-lockable version is shipped with the Secured Silicon
Sector unprotected, allowing customers to utilize the that sector in any manner they choose. The customer-
lockable version has the Secured Silicon Sector Indicator Bit permanently set to a 0. Thus, the Secured
Silicon Sector Indicator Bit prevents customer-lockable devices from being used to replace devices that are
factory locked. The Secured Silicon Customer Indicator Bit (DQ6) is permanently set to 1 if the part has been
customer locked, permanently set to 0 if the part has been factory locked, and is 0 if customer lockable.
The system accesses the Secured Silicon Sector through a command sequence (see
Sector/Exit Secured Silicon Sector Command Sequence on page
Secured Silicon Sector command sequence, it may read the Secured Silicon Sector by using the addresses
normally occupied by the boot sectors. This mode of operation continues until the system issues the Exit
Secured Silicon Sector command sequence, or until power is removed from the device. On power-up, or
following a hardware reset, the device reverts to sending commands to the first 256 bytes of Sector 0. Note
that the ACC function and unlock bypass modes are not available when the Secured Silicon Sector is
enabled.
In a factory locked device, the Secured Silicon Sector is protected when the device is shipped from the
factory. The Secured Silicon Sector cannot be modified in any way. The device is preprogrammed with both a
random number and a secure ESN. The 8-word random number is at addresses 000000h–000007h in word
mode (or 000000h–00000Fh in byte mode). The secure ESN is programmed in the next 8 words at addresses
000008h–00000Fh (or 000010h–00001Fh in byte mode). The device is available preprogrammed with one of
the following:
Contact an your local sales office for details on using Spansion programming services.
If the security feature is not required, the Secured Silicon Sector can be treated as an additional Flash
memory space. The Secured Silicon Sector can be read any number of times, but can be programmed and
locked only once. Note that the accelerated programming (ACC) and unlock bypass functions are not
available when programming the Secured Silicon Sector.
The Secured Silicon Sector area can be protected using one of the following procedures:
Once the Secured Silicon Sector is locked and verified, the system must write the Exit Secured Silicon Sector
Region command sequence to return to reading and writing the remainder of the array.
A random, secure ESN only
Customer code through Spansion programming services
Both a random, secure ESN and customer code through Spansion programming services
Write the three-cycle Enter Secured Silicon Sector Region command sequence, and then follow the in-
system sector protect algorithm as shown in
V
pin to a high voltage. Note that this method is only applicable to the Secured Silicon Sector.
To verify the protect/unprotect status of the Secured Silicon Sector, follow the algorithm shown in
Figure 8.3 on page
IH
or V
ID
. This allows in-system protection of the Secured Silicon Sector Region without raising any device
27.
S29JL064H
D a t a
Figure 8.2 on page
S h e e t
32). After the system has written the Enter
25, except that RESET# may be at either
S29JL064H_00_A7 September 19, 2007
Enter Secured Silicon