During the reset sequence, fields NVM_EEPROT[DPOPEN] and NVM_EEPROT[DPS]
are loaded with the contents of the EEPROM protection byte in the flash configuration
field at global address 0xFF7D located in flash memory. EEPROM protection address
range is specified by the NVM_EEPROT[DPS].
Table 4-15. EEPROM protection address range
DPS[1:0]
Global address range
Protected size
00
0x3100 – 0x311F
32 bytes
01
0x3100 – 0x313F
64 bytes
10
0x3100 – 0x315F
96 bytes
11
0x3100 – 0x317F
128 bytes
All possible flash protection scenarios are shown in
scheme is loaded from the flash memory at global address 0xFF7C during the reset
sequence, it can be changed by the user.
4.5.2.7 Security
The flash and EEPROM module provides security information to the MCU. The flash
security state is defined by the NVM_FSEC[SEC] bits. During reset, the flash module
initializes the NVM_FSEC register using data read from the security byte of the flash and
EEPROM configuration field at global address 0xFF7F. The security state out of reset
can be permanently changed by programming the security byte, assuming that the MCU
is starting from a mode where the necessary flash and EEPROM erase and program
commands are available and that the upper region of the flash is unprotected. If the flash
security byte is successfully programmed, its new value will take affect after the next
MCU reset.
The following subsections describe these security-related subjects:
• Unsecuring the MCU using backdoor key access
• Unsecuring the MCU using BDM
• Mode and security effects on flash and EEPROM command availability
4.5.2.7.1 Unsecuring the MCU using backdoor key access
The MCU may be unsecured by using the backdoor key access feature which requires
knowledge of the contents of the backdoor keys, which are four 16-bit words
programmed at addresses 0xFF70–0xFF77. If the KEYEN[1:0] bits are in the enabled
Flash and EEPROM
MC9S08PA4 Reference Manual, Rev. 5, 08/2017
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NXP Semiconductors
Summary of Contents for MC9S08PA4
Page 1: ...MC9S08PA4 Reference Manual Supports MC9S08PA4 Document Number MC9S08PA4RM Rev 5 08 2017 ...
Page 2: ...MC9S08PA4 Reference Manual Rev 5 08 2017 2 NXP Semiconductors ...
Page 22: ...MC9S08PA4 Reference Manual Rev 5 08 2017 22 NXP Semiconductors ...
Page 28: ...System clock distribution MC9S08PA4 Reference Manual Rev 5 08 2017 28 NXP Semiconductors ...
Page 150: ...Port data registers MC9S08PA4 Reference Manual Rev 5 08 2017 150 NXP Semiconductors ...
Page 196: ...Human machine interfaces HMI MC9S08PA4 Reference Manual Rev 5 08 2017 196 NXP Semiconductors ...
Page 224: ...Instruction Set Summary MC9S08PA4 Reference Manual Rev 5 08 2017 224 NXP Semiconductors ...
Page 232: ...Functional Description MC9S08PA4 Reference Manual Rev 5 08 2017 232 NXP Semiconductors ...
Page 258: ...FTM Interrupts MC9S08PA4 Reference Manual Rev 5 08 2017 258 NXP Semiconductors ...
Page 294: ...Functional description MC9S08PA4 Reference Manual Rev 5 08 2017 294 NXP Semiconductors ...
Page 398: ...Resets MC9S08PA4 Reference Manual Rev 5 08 2017 398 NXP Semiconductors ...
Page 400: ...MC9S08PA4 Reference Manual Rev 5 08 2017 400 NXP Semiconductors ...