mc9s12vr48 Freescale Semiconductor, Inc, mc9s12vr48 Datasheet - Page 478

• Manufacturer Part Number: mc9s12vr48
• Description: S12 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

64 KByte Flash Module (S12FTMRG64K512V1)
17.3.2.9.1
The general guideline is that P-Flash protection can only be added and not removed. Table 17-20 specifies
all valid transitions between P-Flash protection scenarios. Any attempt to write an invalid scenario to the
FPROT register will be ignored. The contents of the FPROT register reflect the active protection scenario.
See the FPHS and FPLS bit descriptions for additional restrictions.
17.3.2.10 EEPROM Protection Register (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 0x3_FF0D located in
P-Flash memory (see
that will be loaded during the reset sequence, the P-Flash sector containing the EEPROM protection byte
478
Offset Module Base + 0x0009
Reset
W
R
DPOPEN
1
7
P-Flash Protection Restrictions
1
Protection
Allowed transitions marked with X, see
Scenario
From
= Unimplemented or Reserved
Table
0
1
2
3
4
5
6
7
0
0
6
Figure 17-13. EEPROM Protection Register (EEPROT)
Table 17-20. P-Flash Protection Scenario Transitions
17-3) as indicated by reset condition F in . To change the EEPROM protection
X
X
0
MC9S12VR Family Reference Manual,
Preliminary - Subject to Change Without Notice
0
0
5
X
X
X
X
1
X
X
X
X
2
To Protection Scenario
0
0
4
Figure 17-12
3
X
X
X
X
X
X
X
X
X
X
X
X
4
for a definition of the scenarios.
1
3
Rev. 2.2
1
X
X
5
1
2
X
X
6
DPS[3:0]
Freescale Semiconductor
X
7
1
1
1
0