Document Number: 002-00948 Rev. *C
S29CD032J
S29CD016J
S29CL032J
S29CL016J
9.1
Secured Silicon Sector Protection Bit
The Secured Silicon Sector can be shipped unprotected, allowing customers to utilize that sector in any manner they choose.
Please note the following:
The Secured Silicon Sector can be read any number of times, but can be programmed and locked only once. The Secured Silicon
Sector Protection Bit 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.
Once the Secured Silicon Sector is locked and verified, the system must write the Exit Secured Silicon Sector Region command
sequence to return the device to the memory array.
9.2
Secured Silicon Sector Entry and Exit Commands
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 the
Table 34. Memory Array Command Definitions (x32 Mode) on page 67
and
Sector Protection Command Definitions (x32 Mode) on page 68
for address and data requirements for both command sequences.
The Secured Silicon Sector Entry Command allows the following commands to be executed
Read Secured Silicon areas
Program Secured Silicon Sector (only once)
After the system has written the Enter Secured Silicon Sector command sequence, it can read the Secured Silicon Sector by using
the addresses listed in
. This mode of operation continues until the system issues the Exit Secured Silicon
Sector command sequence, or until power is removed from the device.