mc9s08dn60 Freescale Semiconductor, Inc, mc9s08dn60 Datasheet - Page 46

• Manufacturer Part Number: mc9s08dn60
• Description: Hcs08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

0xFFAE
0xFFAF
0xFFB0–
0xFFB7
0xFFBC
0xFFBD
0xFFBE
0xFFBF
Chapter 4 Memory
0xFFB8–
Provided the key enable (KEYEN) bit is 1, the 8-byte comparison key can be used to temporarily
disengage memory security. This key mechanism can be accessed only through user code running in secure
memory. (A security key cannot be entered directly through background debug commands.) This security
key can be disabled completely by programming the KEYEN bit to 0. If the security key is disabled, the
only way to disengage security is by mass erasing the Flash if needed (normally through the background
debug interface) and verifying that Flash is blank. To avoid returning to secure mode after the next reset,
program the security bits (SEC) to the unsecured state (1:0).
46
Address
Reserved for
storage of FTRIM
Res. for storage of
MCGTRM
NVBACKKEY
Reserved
NVPROT
Reserved
NVOPT
Register Name
KEYEN
Bit 7
—
—
—
0
Table 4-4. Nonvolatile Register Summary
EPS
MC9S08DN60 Series Data Sheet, Rev 2
FNORED EPGMOD
—
—
—
6
0
—
—
—
5
0
8-Byte Comparison Key
—
—
—
4
0
0
TRIM
—
—
—
3
0
0
FPS
—
—
—
2
0
0
Freescale Semiconductor
—
—
—
1
0
SEC
FTRIM
Bit 0
—
—
—