Document Number: 002-00886 Rev. *B
S29GL01GP
S29GL512P
S29GL256P
S29GL128P
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 Cypress programming service.
Customers may opt to have their code programmed through the Cypress programming services. Cypress programs the customer's
code, with or without the random ESN. The devices are then shipped from the Cypress factory with the Secured Silicon Sector
permanently locked. Contact your local representative for details on using Cypress programming services.
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