MC9S12E64CFUE Datasheet, PDF (92/606 Pages) Freescale Semiconductor, Inc – Microcontrollers

Chapter 2 128 Kbyte Flash Module (FTS128K1V1)
Table 2-4. FSEC Field Descriptions
Field
Description
7–6
Backdoor Key Security Enable Bits — The KEYEN[1:0] bits define the enabling of the backdoor key access
KEYEN[1:0] to the Flash module as shown in Table 2-5.
5–2
Nonvolatile Flag Bits — The NV[5:2] bits are available to the user as nonvolatile flags.
NV[5:2]
1–0
Flash Security Bits — The SEC[1:0] bits define the security state of the MCU as shown in Table 2-6. If the Flash
SEC[1:0] module is unsecured using backdoor key access, the SEC[1:0] bits are forced to 1:0.
Table 2-5. Flash KEYEN States
KEYEN[1:0]
Status of Backdoor Key Access
00
DISABLED
01¹
DISABLED
10
ENABLED
11
DISABLED
1 _{Preferred KEYEN state to disable Backdoor Key Access.}
Table 2-6. Flash Security States
SEC[1:0]
Status of Security
00
Secured
01¹
Secured
10
Unsecured
11
Secured
1 _{Preferred SEC state to set MCU to secured state.}
The security function in the Flash module is described in Section 2.4.3, “Flash Module Security”.
2.3.2.3 RESERVED1
This register is reserved for factory testing and is not accessible to the user.
Module Base + 0x0002
7
6
5
4
3
2
1
0
R
0
0
0
0
0
0
0
0
W
Reset
0
0
0
0
0
0
0
0
= Unimplemented or Reserved
Figure 2-6. RESERVED1
All bits read 0 and are not writable.
MC9S12E128 Data Sheet, Rev. 1.07
92
Freescale Semiconductor