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**                                                                    **
**                 Application notes for Saifun devices               **
**                                                                    **
**                       (Informal Document)                          **
**                                                                    **
**    To find the application notes for your device search for the    **
**    'core' part name.  As an example using the 25F020 8 pin SOIC    **
**    you would search this document for the entry "25F020"           **
**                                                                    **
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 25F005
 ----------
 25F010
 ----------
 25F020
 ----------
 
 There are four levels of Block Protection that can be supported
 on these devices:
                                           Start/End Block
                         (BP1), (BP0)    Protection Addresses
 Security Fuse settings:   SF2,   SF1  25F005        25F010
 ------------------------------------  ------------  --------------
                             0,     0  None          None          
                             0,     1  $8000->$FFFF  $18000->$1FFFF
                             1,     0  $8000->$FFFF  $10000->$1FFFF
                             1,     1  $0000->$FFFF  $00000->$1FFFF
 ------------------------------------------------------------------

                                            Start/End Block
                         (BP1), (BP0)     Protection Addresses
 Security Fuse settings:   SF2,   SF1     25F020
 ------------------------------------     --------------------
                             0,     0     None
                             0,     1     $30000->$3FFFF
                             1,     0     $20000->$3FFFF
                             1,     1     $00000->$3FFFF
 ---------------------------------------------------------------

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

 NOTE: The "Erase EE device" option must be enabled when re-programming
       the device in order to remove the Block Protection.

 NOTE: The "Erase EE device" option will NOT Erase the device. 
       To re-program the disable Blank/Illegal Bit checks flags.

 To program the Hardware Write Protection option enable the "Program
 security fuse 3" flag.

 Performing a Load operation will also load the Status Register
 Protection Bits into the following address locations in User RAM:
 25F005 = Address $10000
 25F010 = Address $20000
 25F020 = Address $40000

 The data format in the Programmer's User RAM will follow the same
 format as defined in the corresponding device's data sheet.

 Status Register Format in relation to the Protection Bits:
  --------------------------------------------------------
 | Bit 7 |Bit 6 |Bit 5 |Bit 4 |Bit 3 |Bit 2 |Bit 1 |Bit 0 |
 |--------------------------------------------------------|
 | WPBEN |  X   |  X   |  X   | BP1  | BP0  |  X   |  X   |
  --------------------------------------------------------

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