mc9s08ac16 Freescale Semiconductor, Inc, mc9s08ac16 Datasheet - Page 59

• Manufacturer Part Number: mc9s08ac16
• Description: Hcs08 Microcontrollers 8-bit Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

SEC01:SEC00 changes to 1:0 after successful backdoor key entry or a successful blank check of FLASH.
4.6.3
Bits 7 through 5 may be read or written at any time. Bits 4 through 0 always read 0 and cannot be written.
Freescale Semiconductor
KEYACC
Reset
Field
5
W
R
FLASH Configuration Register (FCNFG)
Enable Writing of Access Key — This bit enables writing of the backdoor comparison key. For more detailed
information about the backdoor key mechanism, refer to
0 Writes to 0xFFB0–0xFFB7 are interpreted as the start of a FLASH programming or erase command.
1 Writes to NVBACKKEY (0xFFB0–0xFFB7) are interpreted as comparison key writes.
0
0
7
= Unimplemented or Reserved
0
0
6
Figure 4-7. FLASH Configuration Register (FCNFG)
SEC01:SEC00
Table 4-10. FCNFG Register Field Descriptions
0:0
0:1
1:0
1:1
KEYACC
MC9S08AC16 Series Data Sheet, Rev. 0
0
5
Table 4-9. Security States
PRELIMINARY
0
0
4
Description
Section 4.5,
3
0
0
Description
unsecured
secure
secure
secure
“Security.”
0
0
2
0
0
1
Chapter 4 Memory
0
0
0
59