Chapter 17 Flash Memory
MPC5602P Microcontroller Reference Manual, Rev. 4
Freescale Semiconductor
377
When some Flash sectors are used to perform an EEPROM emulation, it is recomended for safety reasons
to reserve at least three sectors for this purpose.
17.3.8.4
Protection strategy
Two kinds of protection are available: Modify Protection to avoid unwanted program/erase in Flash
sectors, and Censored mode to avoid piracy.
17.3.8.4.1
Modify protection
The Flash modify protection information is stored in non-volatile Flash cells located in the TestFlash. This
information is read once during the Flash initialization phase following the exit from reset and they are
stored in Volatile registers that act as actuators.
The reset state of all the volatile modify protection registers is the protected state.
All the non-volatile modify protection registers can be programmed through a normal double word
program operation at the related locations in TestFlash.
The non-volatile modify protection registers cannot be erased.
•
The non-volatile modify protection registers are physically located in TestFlash. Their bits can be
programmed to 0 only once, after which they cannot be restored to 1.
•
The volatile modify protection registers are read/write registers containing bits that can be written
at 0 or 1 by the user application.
Table 17-37. Bits manipulation: double words with the same ECC value
Double word
ECC value – All 1s No Error
0xFFFF_FFFF_FFFF_FFFF
0xFF
0xFFFF_FFFF_FFFF_0000
0xFF
0xFFFF_FFFF_0000_FFFF
0xFF
0xFFFF_0000_FFFF_FFFF
0xFF
0x0000_FFFF_FFFF_FFFF
0xFF
0xFFFF_FFFF_0000_0000
0xFF
0xFFFF_0000_FFFF_0000
0xFF
0x0000_FFFF_FFFF_0000
0xFF
0xFFFF_0000_0000_FFFF
0xFF
0x0000_FFFF_0000_FFFF
0xFF
0x0000_0000_FFFF_FFFF
0xFF
0xFFFF_0000_0000_0000
0xFF
0x0000_FFFF_0000_0000
0xFF
0x0000_0000_0000_0000
0xFF