Datasheet

4.6.9 EEPROM Protection Register (NVM_EEPROT)
The EEPROT register defines which EEPROM sectors are protected against program and
erase operations.
The unreserved bits of the EEPROT register are writable with the restriction that
protection can be added but not removed. Writes must increase the DPS value and the
DPOPEN bit can only be written from 1, protection disabled, to 0, protection enabled. If
the DPOPEN bit is set, the state of the DPS bits is irrelevant.
During the reset sequence, fields DPOPEN and DPS of the EEPROT register are loaded
with the contents of the EEPROM protection byte in the flash configuration field at
global address 0xFF7D located in flash memory. To change the EEPROM protection that
will be loaded during the reset sequence, the flash sector containing the EEPROM
protection byte must be unprotected. Then the EEPROM protection byte must be
programmed.
Trying to alter data in any protected area in the EEPROM memory will result in a
protection violation error and the FPVIOL bit will be set in the FSTAT register. Block
erase of the EEPROM memory is not possible if any of the EEPROM sectors are
protected.
Address: 3020h base + 9h offset = 3029h
Bit 7 6 5 4 3 2 1 0
Read
DPOPEN
0
DPS
Write
Reset
x* x* x* x* x* x* x* x*
* Notes:
x = Undefined at reset.•
NVM_EEPROT field descriptions
Field Description
7
DPOPEN
EEPROM Protection Control
0 Enables EEPROM memory protection from program and erase with protected address range defined
by DPS bits.
1 Disables EEPROM memory protection from program and erase.
6–3
Reserved
This field is reserved.
This read-only field is reserved and always has the value 0.
2–0
DPS
EEPROM Protection Size
These bits determine the size of the protected area in the EEPROM memory.
Chapter 4 Memory map
MC9S08PA60 Reference Manual, Rev. 1, 9/2012
Freescale Semiconductor, Inc. 113