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Chapter 1 Device Overview MC9S12ZVM-Family
MC9S12ZVM Family Reference Manual Rev. 1.3
Freescale Semiconductor
53
NOTE
No backdoor key word is allowed to have the value 0x0000 or 0xFFFF.
1.10.5
Reprogramming the Security Bits
Security can also be disabled by erasing and reprogramming the security bits within the flash
options/security byte to the unsecured value. Since the erase operation will erase the entire sector
(0x7F_FE00–0x7F_FFFF) the backdoor key and the interrupt vectors will also be erased; this method is
not recommended for normal single chip mode. The application software can only erase and program the
Flash options/security byte if the Flash sector containing the Flash options/security byte is not protected
(see Flash protection). Thus Flash protection is a useful means of preventing this method. The
microcontroller enters the unsecured state after the next reset following the programming of the security
bits to the unsecured value.
This method requires that:
•
The application software previously programmed into the microcontroller has been designed to
have the capability to erase and program the Flash options/security byte.
•
The Flash sector containing the Flash options/security byte is not protected.
1.10.6
Complete Memory Erase
The microcontroller can be unsecured by erasing the entire EEPROM and Flash memory contents. If
ERASE_FLASH is successfully completed, then the Flash unsecures the device and programs the security
byte automatically.
1.11
Resets and Interrupts
1.11.1
Resets
Table 1-12. lists all reset sources and the vector locations. Resets are explained in detail in the
“S12 Clock, Reset and Power Management Unit (S12CPMU_UHV_V6)
”
.
Table 1-12. Reset Sources and Vector Locations
Vector Address
Reset Source
CCR
Mask
Local Enable
0xFFFFFC
Power-On Reset (POR)
None
None
Low Voltage Reset (LVR)
None
None
External pin RESET
None
None
Clock monitor reset
None
OSCE Bit in CPMUOSC register
COP watchdog reset
None
CR[2:0] in CPMUCOP register
Содержание MC9S12ZVM series
Страница 116: ...Chapter 2 Port Integration Module S12ZVMPIMV1 MC9S12ZVM Family Reference Manual Rev 1 3 116 Freescale Semiconductor ...
Страница 242: ...Chapter 7 ECC Generation Module SRAM_ECCV1 MC9S12ZVM Family Reference Manual Rev 1 3 242 Freescale Semiconductor ...
Страница 384: ...Chapter 10 Supply Voltage Sensor BATSV3 MC9S12ZVM Family Reference Manual Rev 1 3 384 Freescale Semiconductor ...
Страница 484: ...Chapter 13 Programmable Trigger Unit PTUV2 MC9S12ZVM Family Reference Manual Rev 1 3 484 Freescale Semiconductor ...
Страница 662: ...Chapter 17 Gate Drive Unit GDUV4 MC9S12ZVM Family Reference Manual Rev 1 3 662 Freescale Semiconductor ...
Страница 684: ...Chapter 18 LIN Physical Layer S12LINPHYV2 MC9S12ZVM Family Reference Manual Rev 1 3 684 Freescale Semiconductor ...
Страница 740: ...Chapter 19 128 KB Flash Module S12ZFTMRZ128K512V2 MC9S12ZVM Family Reference Manual Rev 1 3 740 Freescale Semiconductor ...
Страница 756: ...Appendix A MCU Electrical Specifications MC9S12ZVM Family Reference Manual Rev 1 3 756 Freescale Semiconductor ...
Страница 772: ...Appendix D LINPHY Electrical Specifications MC9S12ZVM Family Reference Manual Rev 1 3 772 Freescale Semiconductor ...
Страница 776: ...Appendix E GDU Electrical Specifications MC9S12ZVM Family Reference Manual Rev 1 3 776 Freescale Semiconductor ...
Страница 788: ...Appendix I MSCAN Electrical Specifications MC9S12ZVM Family Reference Manual Rev 1 3 788 Freescale Semiconductor ...
Страница 790: ...Appendix J Package Information MC9S12ZVM Family Reference Manual Rev 1 3 790 Freescale Semiconductor ...