mc9s12q128 Freescale Semiconductor, Inc, mc9s12q128 Datasheet - Page 504

• Manufacturer Part Number: mc9s12q128
• Description: Hcs12 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Chapter 18 64 Kbyte Flash Module (S12FTS64KV4)
The security function in the Flash module is described in
18.3.2.3
This register is reserved for factory testing and is not accessible to the user.
All bits read 0 and are not writable.
504
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
Flash 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. Preferred SEC state to set MCU to secured state.
KEYEN[1:0]
SEC[1:0]
01
01
00
10
11
00
10
11
Table 18-4. FSEC Field Descriptions
(1)
(1)
Table 18-6. Flash Security States
Table 18-5. Flash KEYEN States
0
0
5
Table
Figure 18-6. RESERVED1
18-5.
Status of Backdoor Key Access
MC9S12Q128
Rev 1.09
0
0
4
Status of Security
Description
Unsecured
Secured
Secured
Secured
DISABLED
DISABLED
DISABLED
ENABLED
Section 18.4.3, “Flash Module
0
0
3
0
0
2
Freescale Semiconductor
0
0
1
Table
Security”.
18-6. If the
0
0
0