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**                                                                    **
**      Application notes for NexFlash FLASH memory devices           **
**                                                                    **
**                       (Informal Document)                          **
**                                                                    **
**  To find the application notes for your device search for the      **
**  'core' part name.  As an example using the NX25P20 8 pin SOIC     **
**  you would search on '25P20'                                       **
**                                                                    **
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25P10
----------
25P20
----------

1.Four levels of "BLOCK PROTECT" can be implemented
for these device as follows:

Security Fuse     Block Protect Start Addresses  

 SF2     SF1      25P10         25P20
-------------     ------------  -----------  
  0       0       None          None         
  0       1       None          $30000-3FFFF 
  1       0       None          $20000-3FFFF 
  1       1       $0-FFFF       $00000-3FFFF     

2.Enabling the "Erase EE device" option will remove all block protection.

NOTE: Devices require "Erase EE device" option to be enabled when re-programming.

3. Status Register Format:  

 ,_______________________________________________________________________
 |        |        |        |        |        |        |        |        |
 |  SRWD  |   0    |   0    |   0    |  BP1   |  BP0   |  WEL   |  WIP   |
 |        |        |        |        |        |        |        |        |
 `-----------------------------------------------------------------------`
   Bit 7     Bit 6    Bit 5    Bit 4    Bit 3    Bit 2    Bit 1    Bit 0

Address of status register:
25P10: $20000
25P20: $40000

4.Setting the "Program Protect Register" to Yes allows programming of
the 'Status Register Write Disable' (SRWD) bit.

For enabling "Program Protect Register" in TaskLink for windows(TLwin)
or TaskLink for DOS(TLdos) you must set the Enable Special Data #2
option.

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