MC9S12C Datasheet, PDF (542/680 Pages) Motorola, Inc – 16-Bit Microcontroller

Chapter 19 64 Kbyte Flash Module (S12FTS64KV4)
Table 19-4. 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 19-5.
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 19-6. If the
SEC[1:0] Flash module is unsecured using backdoor key access, the SEC[1:0] bits are forced to 1:0.
Table 19-5. Flash KEYEN States
KEYEN[1:0]
Status of Backdoor Key Access
00
01⁽¹⁾
DISABLED
DISABLED
10
ENABLED
11
DISABLED
1. Preferred KEYEN state to disable Backdoor Key Access.
Table 19-6. Flash Security States
SEC[1:0]
Status of Security
00
01⁽¹⁾
Secured
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 19.4.3, “Flash Module Security”.
19.3.2.3 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 19-6. RESERVED1
All bits read 0 and are not writable.
542
MC9S12C-Family / MC9S12GC-Family
Freescale Semiconductor
Rev 01.23