user manual
Block Guide — S12EETX4KV0 V00.04
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3.3.5 EPROT — EEPROM Protection Register
The EPROT register defines which EEPROM sectors are protected against program or erase operations.
Figure 3-6 EEPROM Protection Register (EPROT)
All bits in the EPROT register are readable and writable except for RNV[6:4] which are only readable.
The EPOPEN and EPDIS bits can only be written to the protected state. The EPS bits can be written
anytime until bit EPDIS is cleared. If the EPOPEN bit is cleared, the state of the EPDIS and EPS bits is
irrelevant.
During the reset sequence, the EPROT register is loaded from the EEPROM Protection byte at address
offset $_FFD (see Table 3-1 EEPROM Configuration Field). To change the EEPROM protection that
will be loaded during the reset sequence, the EEPROM memory must be unprotected, then the EEPROM
Protection byte must be reprogrammed. Trying to alter data in any protected area in the EEPROM memory
will result in a protection violation error and the PVIOL flag will be set in the ESTAT register. The mass
erase of an EEPROM block is possible only when protection is fully disabled by setting the EPOPEN and
EPDIS bits.
EPOPEN — Opens the EEPROM for program or erase.
1 = The EEPROM sectors not protected are enabled for program or erase.
0 = The entire EEPROM memory is protected from program and erase.
RNV[6:4] — Reserved Non-Volatile Bits.
The RNV[6:4] bits should remain in the erased state “1” for future enhancements.
EPDIS — EEPROM Protection address range Disable.
The EPDIS bit determines whether there is a protected area in a specific region of the EEPROM
memory ending with address offset $_FFF.
1 = Protection disabled.
0 = Protection enabled.
EPS[2:0] — EEPROM Protection Address Size.
The EPS[2:0] bits determine the size of the protected area as shown inTable 3-3. The EPS bits can
only be written to while the EPDIS bit is set.
Address Offset: $_04
7 6 543210
R
EPOPEN
RNV6 RNV5 RNV4
EPDIS EPS2 EPS1 EPS0
W
Reset:
F F FFFFFF
= Unimplemented or Reserved
Frees
cale Semiconductor,
I
Freescale Semiconductor, Inc.
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