
Chapter 20 96 Kbyte Flash Module (S12FTS96KV1)
Freescale Semiconductor
MC9S12C-Family / MC9S12GC-Family
589
Rev 01.24
Figure 20-11. Flash Protection Scenarios
20.3.2.5.1
Flash Protection Restrictions
The general guideline is that protection can only be added, not removed. All valid transitions between
Flash protection scenarios are specied in
Table 20-13. 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.
Table 20-13. Flash Protection Scenario Transitions
From
Protection
Scenario
To Protection Scenario(1)
01234567
0
XXXX
1X
X
2X
X
3X
4X
X
5
XXXX
7
6
5
4
FPOPEN
=
1
3
2
1
0
FPHS[1:0]
FPLS[1:0]
FPOPEN
=
0
FPHDIS = 1
FPLDIS = 1
FPHDIS = 1
FPLDIS = 0
FPHDIS = 0
FPLDIS = 1
FPHDIS = 0
FPLDIS = 0
Scenario
Protected Flash
FPHS[1:0]
FPLS[1:0]
0xFFFF