Flash Memory
MPC5606S Microcontroller Reference Manual, Rev. 7
632 Freescale Semiconductor
17.3.8.3 EEPROM emulation
When some flash memory sectors are used to perform an EEPROM emulation, it is recommended for
safety reasons to reserve at least 3 sectors to this purpose.
17.3.9 Protection strategy
Two kind of protections are available: Modify Protection to avoid unwanted program/erase in flash
memory sectors and Censored mode to avoid piracy.
17.3.9.1 Modify protection
The flash memory modify protection information is stored in non-volatile flash memory cells located in
the Test flash. This information is read once during the flash memory initialization phase following the exit
from Reset and is 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 Test flash.
The non-volatile modify protection registers cannot be erased.
• The non-volatile modify protection registers are physically located in Test flash, their bits can be
programmed to 0 only once and they can no more be restored to 1.
Table 17-60. Bit manipulation: double words with the same ECC value
Double Word ECC
0xFFFF_FFFF_FFFF_FFFF 0xFF
0xFFFF_FFFF_FFFF_0000
0xFFFF_FFFF_0000_FFFF
0xFFFF_0000_FFFF_FFFF
0x0000_FFFF_FFFF_FFFF
0xFFFF_FFFF_0000_0000
0xFFFF_0000_FFFF_0000
0x0000_FFFF_FFFF_0000
0xFFFF_0000_0000_FFFF
0x0000_FFFF_0000_FFFF
0x0000_0000_FFFF_FFFF
0xFFFF_0000_0000_0000
0x0000_FFFF_0000_0000
0x0000_0000_0000_0000
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