![](http://datasheet.mmic.net.cn/160000/W78M64VP120SBM_datasheet_10290422/W78M64VP120SBM_16.png)
16
White Electronic Designs Corporation (602) 437-1520 www.whiteedc.com
White Electronic Designs
W78M64VP-XSBX
October 2008
Rev. 2
ADVANCED
White Electronic Designs Corp. reserves the right to change products or specications without notice.
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.
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 modied in any way.
The accelerated programming (ACC) and unlock
bypass functions are not available when the Secured
Silicon Sector is enabled.
Once the Secured Silicon Sector is locked and
veried, the system must write the Exit Secured
Silicon Sector Region command sequence which
return the device to the memory array at sector 0.
SECURED SILICON SECTOR ENTRY/
EXIT COMMAND SEQUENCES
The system can access the Secured Silicon Sector region
by issuing the three-cycle Enter Secured Silicon Sector
command sequence. The device continues to access
the Secured Silicon Sector region until the system issues
the four-cycle Exit Secured Silicon Sector command
sequence.
See Command Definitions [Secured Silicon Sector
Command Table, Appendix
Table 38 for address and data requirements for both
command sequences.
The Secured Silicon Sector Entry Command allows the
following commands to be executed
Read customer and factory Secured Silicon areas
Program the customer Secured Silicon Sector
After the system has written the Enter Secured Silicon
Sector command sequence, it may read the Secured Silicon
Sector by using the addresses normally occupied by sector
SA0 within the memory array. This mode of operation
continues until the system issues the Exit Secured Silicon
Sector command sequence, or until power is removed from
the device.