MC9S12E32CFU FREESCALE [Freescale Semiconductor, Inc], MC9S12E32CFU Datasheet - Page 92

• Manufacturer Part Number: MC9S12E32CFU
• Description: HCS12 Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Chapter 2 128 Kbyte Flash Module (FTS128K1V1)
The security function in the Flash module is described in
2.3.2.3
This register is reserved for factory testing and is not accessible to the user.
All bits read 0 and are not writable.
92
Module Base + 0x0002
KEYEN[1:0]
SEC[1:0]
NV[5:2]
Reset
Field
7–6
5–2
1–0
W
R
Backdoor Key Security Enable Bits — The KEYEN[1:0] bits define the enabling of the backdoor key access
to the Flash module as shown in
Nonvolatile Flag Bits — The NV[5:2] bits are available to the user as nonvolatile flags.
Flash Security Bits — The SEC[1:0] bits define the security state of the MCU as shown in
module is unsecured using backdoor key access, the SEC[1:0] bits are forced to 1:0.
RESERVED1
0
0
7
= Unimplemented or Reserved
0
0
6
1
Preferred KEYEN state to disable Backdoor Key Access.
1
KEYEN[1:0]
SEC[1:0]
Preferred SEC state to set MCU to secured state.
01
01
00
10
11
00
10
11
Table 2-4. FSEC Field Descriptions
1
1
Table 2-6. Flash Security States
MC9S12E128 Data Sheet, Rev. 1.07
Table 2-5. Flash KEYEN States
0
0
5
Table
Figure 2-6. RESERVED1
2-5.
Status of Backdoor Key Access
0
0
4
Status of Security
Description
Unsecured
Secured
Secured
Secured
DISABLED
DISABLED
DISABLED
ENABLED
Section 2.4.3, “Flash Module
0
0
3
0
0
2
Freescale Semiconductor
Table
0
0
1
Security”.
2-6. If the Flash
0
0
0