
28F6408W30, 28F3204W30, 28F320W30, 28F640W30
32
Preliminary
9.0
Flash Protection Register
The 1.8 Volt Intel
 Wireless Flash Memory includes a 128-bit protection register. This protection 
register can be used to increase system security and/or for identification purposes. The protection 
register value can match the flash component to the system
’
s CPU or ASIC to prevent device 
substitution.
The lower 64-bit segments within the protection register are programmed by Intel with a unique 
number in each flash device. The upper 64-bit segments within the protection register are left for 
the customer to program. Once programmed, the customer segment can be locked to prevent 
further reprogramming.
The protection register shares some of the same internal flash resources as the parameter partition. 
Therefore, read-while-write is only allowed between the protection register and main partitions. 
Table 15
 describes the operation allowed using read-while-write/erase with the protection register.
9.1
Protection Register Read
Writing the Read Identifier command allows the protection register data to be read 16 bits at a time 
from addresses shown in 
Table 11, 
“
Device Identification Codes
”
 on page 21
. The ID plane, 
containing the protection registers, appears over partition addresses corresponding to the partition 
address supplied with the command. Writing the Read Array command returns the device to read 
array mode.
9.2
Program Protection Register
The Protection Program command should be issued only at the bottom partition followed by the 
data to be programed at the specified location. It programs the 64-bit user protection register 16 bits 
at a time. 
Table 11, 
“
Device Identification Codes
”
 on page 21
 and 
Table 16, 
“
Protection Register 
Table 15. Simultaneous Operations Allowed with the Protection Register
Protection 
Register 
Parameter 
Partition
Array Data
Main
Partition
Notes
Read
Conditional
–
See Notes
Write/Erase
While programming or erasing in a main partition, the protection register may 
be read from any other partition. Reading the parameter partition data is not 
allowed if the protection register is being read from addresses within the 
parameter partition.
While programming or erasing in a main partition, read operations are allowed 
in the parameter partition. Accessing the protection registers from parameter 
partition addresses is not allowed.
While programming or erasing in a main partition, read operations are allowed 
in the parameter partition. Accessing the protection registers in a partition that 
is 
different
 from the one being programed/erased, and also 
different
 from the 
parameter partition, is allowed.
While programming the protection register, reads are only allowed in the other 
main partitions. Access to the parameter partition is not allowed. This is 
because programming of the protection register can only occur in the 
parameter partition, so it will exist in status mode.
While programming or erasing the parameter partition, reads of the protection 
registers are not allowed in 
any
 partition. Reads in other main partitions are 
supported. 
Conditional
–
See Notes
Read
Write/Erase
Read
Read
Write/Erase
Write
No Access 
Allowed
Read
No Access 
Allowed
Write/Erase
Read