mc9s08rd60fj Freescale Semiconductor, Inc, mc9s08rd60fj Datasheet - Page 51

• Manufacturer Part Number: mc9s08rd60fj
• Description: Hcs08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

4.6.2 FLASH Options Register (FOPT and NVOPT)
During reset, the contents of the nonvolatile location NVOPT are copied from FLASH into FOPT. Bits 5
through 2 are not used and always read 0. This register may be read at any time, but writes have no meaning
or effect. To change the value in this register, erase and reprogram the NVOPT location in FLASH
memory as usual and then issue a new MCU reset.
KEYEN — Backdoor Key Mechanism Enable
FNORED — Vector Redirection Disable
Freescale Semiconductor
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
When this bit is 1, then vector redirection is disabled.
1 = If user firmware writes an 8-byte value that matches the nonvolatile backdoor key
0 = No backdoor key access allowed.
1 = Vector redirection disabled.
0 = Vector redirection enabled.
(NVBACKKEY through NVBACKKEY+7 in that order), security is temporarily disengaged
until the next MCU reset.
200 kHz
150 kHz
8 MHz
4 MHz
2 MHz
1 MHz
f
Bus
Reset:
Read:
Write:
(Binary)
PRDIV8
Figure 4-5 FLASH Options Register (FOPT)
0
0
0
0
0
0
KEYEN
Table 4-6 FLASH Clock Divider Settings
Bit 7
DIV5:DIV0
= Unimplemented or Reserved
(Decimal)
FNORED
This register is loaded from nonvolatile location NVOPT during reset.
39
19
6
9
4
0
0
MC9S08RC/RD/RE/RG
4.5
Security.
5
0
200 kHz
200 kHz
200 kHz
200 kHz
200 kHz
150 kHz
f
FCLK
0
4
Program/Erase Timing Pulse
(5 s Min, 6.7 s Max)
SoC Guide — MC9S08RG60/D Rev 1.10
3
0
6.7 s
5 s
5 s
5 s
5 s
5 s
0
2
SEC01
1
SEC00
Bit 0
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