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???
05/04/05 21:05
Modified:
  05/04/05 21:08

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#92943 - Individual sector security bits removal
Responding to: ???'s previous message
UM10109_1.pdf (P89LPC932A1 User Manual) on page 123 said:

Table 104: Sector Security Bytes (SECx) bit description

0 MOVCDISx - MOVC Disable. Disables the MOVC command for sector x. Any MOVC that attempts to read a byte in a MOVC protected sector will return invalid data. This bit can only be erased when sector x is erased.

1 SPEDISx - Sector Program Erase Disable x. Disables program or erase of all or part of sector x. This bit and sector
x are erased by either a sector erase command (ISP, IAP, commercial programmer) or a 'global' erase command (commercial programmer).

2 EDISx Erase Disable ISP. Disables the ability to perform an erase of sector x in ISP or IAP mode. When programmed, this bit and sector x can only be erased by a 'global' erase command using a commercial programmer. This bit and sector x CANNOT be erased in ISP or IAP modes.


It means, to prevent readout of the code it is enough to set bit 0, and perhaps set bit 1 to prevent some kind of tampering with it. Both these bits are erased together with erasing the sector.

Unfortunately, it says nothing on effect of these bits on data readout using parallel programming nor ICP, but I believe it would work (otherwise it would have no reason to implement, would it?)
Do you have any information regarding PP/ICP?

Jan Waclawek

List of 46 messages in thread
TopicAuthorDate
ISP-AES(or other tiny encryption)for LPC            01/01/70 00:00      
   so it works?            01/01/70 00:00      
      re so it works?            01/01/70 00:00      
         could it be            01/01/70 00:00      
   TEA            01/01/70 00:00      
      re could it be?            01/01/70 00:00      
         double-xor            01/01/70 00:00      
            LPC935            01/01/70 00:00      
      TEA            01/01/70 00:00      
         Tea time!            01/01/70 00:00      
            TEA time ;)            01/01/70 00:00      
            More tea            01/01/70 00:00      
         Please clarify requirements            01/01/70 00:00      
            what i want, Dan            01/01/70 00:00      
               Looks like you are set then            01/01/70 00:00      
                  to Dan            01/01/70 00:00      
                     Re: to Dan            01/01/70 00:00      
                        Mode of operation            01/01/70 00:00      
                        I underdstand now., thanks            01/01/70 00:00      
   better done in hardware            01/01/70 00:00      
      what about this?            01/01/70 00:00      
         what are you making            01/01/70 00:00      
            theft has to be prevented            01/01/70 00:00      
               either or            01/01/70 00:00      
                  FM is just a "vehicle"...            01/01/70 00:00      
                     but a diesel            01/01/70 00:00      
                        it's easy            01/01/70 00:00      
                           again, why            01/01/70 00:00      
                              unsecure?            01/01/70 00:00      
                                 yes            01/01/70 00:00      
                                    Individual sector security bits removal            01/01/70 00:00      
                           lockbits            01/01/70 00:00      
                              Now i understand!            01/01/70 00:00      
                                 same thing            01/01/70 00:00      
                                    what am i making?            01/01/70 00:00      
                                       be careful            01/01/70 00:00      
                                          why GSM?            01/01/70 00:00      
                                 FM            01/01/70 00:00      
                                    FM            01/01/70 00:00      
   for the xor method to work            01/01/70 00:00      
      RC4            01/01/70 00:00      
         RC4            01/01/70 00:00      
   A reminder            01/01/70 00:00      
      encryption            01/01/70 00:00      
   pgpi.org            01/01/70 00:00      
      ok thanks jez            01/01/70 00:00      

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