Chapter 21 64 KB Flash Module (S12ZFTMRZ64K2KV2)
S12ZVHY/S12ZVHL Family Reference Manual Rev. 1.05
700
Freescale Semiconductor
The security function in the Flash module is described in
21.3.2.3
Flash CCOB Index Register (FCCOBIX)
The FCCOBIX register is used to indicate the amount of parameters loaded into the FCCOB registers for
Flash memory operations.
CCOBIX bits are readable and writable while remaining bits read 0 and are not writable.
5–2
RNV[5:2]
Reserved Nonvolatile Bits
— The RNV bits should remain in the erased state for future enhancements.
1–0
SEC[1:0]
Flash Security Bits
— The SEC[1:0] bits define the security state of the MCU as shown in
. If the
Flash module is unsecured using backdoor key access, the SEC bits are forced to 10.
Table 21-10. Flash KEYEN States
KEYEN[1:0]
Status of Backdoor Key Access
00
DISABLED
01
DISABLED
(1)
1. Preferred KEYEN state to disable backdoor key access.
10
ENABLED
11
DISABLED
Table 21-11. Flash Security States
SEC[1:0]
Status of Security
00
SECURED
01
SECURED
(1)
1. Preferred SEC state to set MCU to secured state.
10
UNSECURED
11
SECURED
Offset Module Base + 0x0002
7
6
5
4
3
2
1
0
R
0
0
0
0
0
CCOBIX[2:0]
W
Reset
0
0
0
0
0
0
0
0
= Unimplemented or Reserved
Figure 21-7. FCCOB Index Register (FCCOBIX)
Table 21-9. FSEC Field Descriptions (continued)
Field
Description
