
50
S29GL-P MirrorBit
 Flash Family
S29GL-P_00_A7 November 8, 2007
D a t a
S h e e t
( P r e l i m i n a r y )
10. Secured Silicon Sector Flash Memory Region
The Secured Silicon Sector provides an extra Flash memory region that enables permanent part identification 
through an Electronic Serial Number (ESN). The Secured Silicon Sector is 128 words in length and all 
Secured Silicon reads outside of the 128-word address range returns invalid data. The Secured Silicon 
Sector Indicator Bit, DQ7, (at Autoselect address 03h) is used to indicate whether or not the Secured Silicon 
Sector is locked when shipped from the factory. 
Please note the following general conditions:
 On power-up, or following a hardware reset, the device reverts to sending commands to the normal 
address space. 
 Reads outside of sector SA0 return memory array data. 
 Sector SA0 is remapped from memory array to Secured Silicon Sector array. 
 Once the Secured Silicon Sector Entry Command is issued, the Secured Silicon Sector Exit command 
must be issued to exit Secured Silicon Sector Mode.
 The Secured Silicon Sector is not accessible when the device is executing an Embedded Program or 
Embedded Erase algorithm. 
 The ACC function and unlock bypass modes are not available when the Secured Silicon Sector is enabled.
10.1
Factory Locked Secured Silicon Sector
The Factory Locked Secured Silicon Sector is always protected when shipped from the factory and has the 
Secured Silicon Sector Indicator Bit (DQ7) permanently set to a “1”. This prevents cloning of a factory locked 
part and ensures the security of the ESN and customer code once the product is shipped to the field. 
These devices are available pre-programmed with one of the following:
 A random, 8 Word secure ESN only within the Secured Silicon Sector (at addresses 000000H - 000007H)
 Both a random, secure ESN and customer code through the Spansion programming service.
Customers may opt to have their code programmed through the Spansion programming services. Spansion 
programs the customer's code, with or without the random ESN. The devices are then shipped from the 
Spansion factory with the Secured Silicon Sector permanently locked. Contact your local representative for 
details on using Spansion programming services. 
10.2
Customer Lockable Secured Silicon Sector
The Customer Lockable Secured Silicon Sector is always shipped unprotected (DQ7 set to “0”), allowing 
customers to utilize that sector in any manner they choose. If the security feature is not required, the Secured 
Silicon Sector can be treated as an additional Flash memory space. 
Please note the following:
 Once the Secured Silicon Sector area is protected, the Secured Silicon Sector Indicator Bit is permanently 
set to “0.”
 The Secured Silicon Sector can be read any number of times, but can be programmed and locked only 
once. The Secured Silicon Sector lock must be used with caution as once locked, there is no procedure 
available for unlocking the Secured Silicon Sector area and none of the bits in the Secured Silicon Sector 
memory space can be modified in any way.
 The accelerated programming (ACC) and unlock bypass functions are not available when the Secured 
Silicon Sector is enabled.
Table 10.1  
Secured Silicon Sector Addresses
Secured Silicon Sector 
Address Range 
Customer Lockable 
ESN Factory Locked 
ExpressFlash Factory Locked 
000000h–000007h 
Determined by 
customer 
ESN 
ESN or determined by customer 
000008h–00007Fh 
Unavailable 
Determined by customer