ColdFire Flash Module (CFM)
MCF52110 ColdFire® Integrated Microcontroller Reference Manual, Rev. 1
17-10
Freescale Semiconductor
Preliminary
The CFMSEC register is loaded from the flash configuration field in the flash block at offset 0x0414
during the reset sequence, indicated by F in
The CFM flash security operation is described in
Section 17.4.3, “Flash Security Operation”
.
17.3.3.4
CFMPROT — CFM Protection Register
The CFMPROT register defines which flash logical sectors are protected against program and erase
operations.
Figure 17-7. CFM Protection Register (CFMPROT)
All CFMPROT register bits are readable and only writable when LOCK=0.
The flash memory is divided into logical sectors for the purpose of data protection using the CFMPROT
register. The flash memory consists of 32 4kByte sectors as shown in <f-helvetica><st-bold>Figure 17-8..
29-16
Reserved, should read 0
15 - 0
SEC
Flash memory security bits
The SEC bits define the security state of the MCU as shown in
, which defines the single code
that enables the security feature in the CFM
Table 17-7. CFM
Security States
SEC[15:0]
Description
0x4AC8
1
1
This value was chosen because it represents the ColdFire HALT instruction, making
it unlikely that a user compiled code accidentally programmed at the security
configuration field location would unintentionally secure the flash memory.
Flash Memory Secured
All other combinations
Flash Memory Unsecured
IPSBAR
Offset: 0x1D_0010 (CFMPROT)
Access: User read/write
31
30
29
28
27
26
25
24
23
22
21
20
19
18
17
16
R
PROTECT
W
Reset
F
1
1
Reset state loaded from flash configuration field during reset.
F
1
F
1
F
1
F
1
F
1
F
1
F
1
F
1
F
1
F
1
F
1
F
1
F
1
F
1
F
1
15
14
13
12
11
10
9
8
7
6
5
4
3
2
1
0
R
PROTECT
W
Reset
F
1
F
1
F
1
F
1
F
1
F
1
F
1
F
1
F
1
F
1
F
1
F
1
F
1
F
1
F
1
F
1
Table 17-6. CFMSEC Field Descriptions
Field
Description