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Section 18.3.3.4, “cfmprot, Cfm protection register, 4 cfmprot — cfm protection register – Freescale Semiconductor ColdFire MCF52210 User Manual

Page 300

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ColdFire Flash Module (CFM)

MCF52211 ColdFire® Integrated Microcontroller Reference Manual, Rev. 2

18-10

Freescale Semiconductor

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

Figure 18-6

.

The CFM flash security operation is described in

Section 18.4.3, “Flash Security Operation”

.

18.3.3.4

CFMPROT — CFM Protection Register

The CFMPROT register defines which flash logical sectors are protected against program and erase
operations.

Figure 18-7. 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 Figure 18-8..

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

Table 18-7

, which defines the single code

that enables the security feature in the CFM

Table 18-7. 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 18-6. CFMSEC Field Descriptions

Field

Description

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