MC9S08DZ16 FREESCALE [Freescale Semiconductor, Inc], MC9S08DZ16 Datasheet - Page 63

• Manufacturer Part Number: MC9S08DZ16
• Description: 8-Bit HCS08 Central Processor Unit (CPU)
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Freescale Semiconductor
EPGMOD
FNORED
Reset
KEYEN
Field
SEC
1:0
7
6
5
W
R
KEYEN
Backdoor Key Mechanism Enable — When this bit is 0, the backdoor key mechanism cannot be used to
disengage security. The backdoor key mechanism is accessible only from user (secured) firmware. BDM
commands cannot be used to write key comparison values that would unlock the backdoor key. For more detailed
information about the backdoor key mechanism, refer to
0 No backdoor key access allowed.
1 If user firmware writes an 8-byte value that matches the nonvolatile backdoor key (NVBACKKEY through
Vector Redirection Disable — When this bit is 1, then vector redirection is disabled.
0 Vector redirection enabled.
1 Vector redirection disabled.
EEPROM Sector Mode — When this bit is 0, each sector is split into two pages (4-byte mode). When this bit is
1, each sector is in a single page (8-byte mode).
0 Half of each EEPROM sector is in Page 0 and the other half is in Page 1.
1 Each sector is in a single page.
Security State Code — This 2-bit field determines the security state of the MCU as shown in
the MCU is secure, the contents of RAM, EEPROM and Flash memory cannot be accessed by instructions from
any unsecured source including the background debug interface. SEC changes to 1:0 after successful backdoor
key entry or a successful blank check of Flash. For more detailed information about security, refer to
4.5.9,
F
7
NVBACKKEY+7 in that order), security is temporarily disengaged until the next MCU reset.
“Security.”
= Unimplemented or Reserved
FNORED
Figure 4-6. Flash and EEPROM Options Register (FOPT)
F
6
1
SEC changes to 1:0 after successful backdoor key entry
or a successful blank check of Flash.
Table 4-9. FOPT Register Field Descriptions
EPGMOD
MC9S08DZ60 Series Data Sheet, Rev. 4
SEC[1:0]
F
5
0:0
0:1
1:0
1:1
Table 4-10. Security States
0
0
4
Description
F = loaded from nonvolatile location NVOPT during reset
Section 4.5.9,
Description
unsecured
secure
secure
secure
3
0
0
1
“Security.”
0
0
2
F
1
Table
Chapter 4 Memory
SEC
4-10. When
Section
F
0
63