Motorola MCF5281, MCF5282 user manual Cfmsec Field Descriptions, SEC150 Description

Models: MCF5282 MCF5281

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Memory Map

Table 6-6. CFMSEC Field Descriptions

Bits

Name

 

Description

 

 

 

31

KEYEN

Enable back door key to security

 

 

1

Back door to Flash is enabled.

 

 

0

Back door to Flash is disabled.

 

 

 

30

SECSTAT

Flash security status

 

 

1

Flash security is enabled

 

 

0

Flash security is disabled

 

 

 

29–16

Reserved. Should be cleared.

 

 

 

15–0

SEC[15:0]

Security field. The SEC bits define the security state of the device; see below.

SEC[15:0]

Description

 

 

0x4AC8

Flash secured 1

All other combinations

Flash unsecured

 

 

1 The 0x4AC8 value was chosen because it represents the ColdFire Halt instruction,

making it unlikely that compiled code accidentally programmed at the security longword in the Flash configuration field location would unintentionally secure the device.

The security features of the CFM are described in Section 6.5, “Flash Security Operation.”

MOTOROLA

Chapter 6. ColdFire Flash Module (CFM)

6-11

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Motorola MCF5281, MCF5282 user manual Cfmsec Field Descriptions, SEC150 Description