Microcontroller User's Manual

MOTOROLA Chapter 6. ColdFire Flash Module (CFM) 6-11
Memory Map
The security features of the CFM are described in Section 6.5, “Flash Security Operation.”
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
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.
All other combinations Flash unsecured