
Chapter 28 256 Kbyte Flash Module (S12XFTX256K2V1)
MC9S12XDP512 Data Sheet, Rev. 2.21
Freescale Semiconductor
1161
28.3.2.5.1
Flash Protection Restrictions
The general guideline is that Flash protection can only be added and not removed.
Table 28-13 species
all valid transitions between Flash protection scenarios. Any attempt to write an invalid scenario to the
FPROT register will be ignored and the FPROT register will remain unchanged. The contents of the
FPROT register reect the active protection scenario. See the FPHS and FPLS descriptions for additional
restrictions.
28.3.2.6
Flash Status Register (FSTAT)
The FSTAT register defines the operational status of the module.
Table 28-13. Flash Protection Scenario Transitions
From
Protection Scenario
To Protection Scenario1
1 Allowed transitions marked with X.
01234567
0
XXXX
1
XX
2
XX
3
X
4
XX
5
XXXX
6
XX
7
XXXXXXXX
76543210
R
CBEIF
CCIF
PVIOL
ACCERR
0
BLANK
0
W
Reset
11000000
= Unimplemented or Reserved
Figure 28-12. Flash Status Register (FSTAT — Normal Mode)
76543210
R
CBEIF
CCIF
PVIOL
ACCERR
0
BLANK
FAIL
0
W
Reset
11000000
= Unimplemented or Reserved
Figure 28-13. Flash Status Register (FSTAT — Special Mode)