Datasheet

Chapter 27 512 Kbyte Flash Module (S12XFTX512K4V2)
MC9S12XDP512 Data Sheet, Rev. 2.21
Freescale Semiconductor 1121
27.3.2.5.1 Flash Protection Restrictions
The general guideline is that Flash protection can only be added and not removed. Table 27-15 specifies
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 reflect the active protection scenario. See the FPHS and FPLS descriptions for additional
restrictions.
27.3.2.6 Flash Status Register (FSTAT)
The FSTAT register defines the operational status of the module.
Table 27-15. Flash Protection Scenario Transitions
From
Protection Scenario
To Protection Scenario
1
1 Allowed transitions marked with X.
01234567
0 XXXX
1 XX
2 XX
3 X
4 XX
5 XXXX
6 XXXX
7 XXXXXXXX
76543210
R
CBEIF
CCIF
PVIOL ACCERR
0 BLANK 0 0
W
Reset 11000000
= Unimplemented or Reserved
Figure 27-12. Flash Status Register (FSTAT — Normal Mode)
76543210
R
CBEIF
CCIF
PVIOL ACCERR
0 BLANK
FAIL
0
W
Reset 11000000
= Unimplemented or Reserved
Figure 27-13. Flash Status Register (FSTAT — Special Mode)