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6175H–ATARM–03-Dec-07
AT91SAM7S Series Preliminary
8.8.3
Lock Regions
8.8.3.1
AT91SAM7S512
Two Embedded Flash Controllers each manage 16 lock bits to protect 16 regions of the flash
against inadvertent flash erasing or programming commands. The AT91SAM7S512 contains 32
lock regions and each lock region contains 64 pages of 256 bytes. Each lock region has a size of
16 Kbytes.
If a locked-region’s erase or program command occurs, the command is aborted and the
LOCKE bit in the MC_FSR register rises and the interrupt line rises if the LOCKE bit has been
written at 1 in the MC_FMR register.
The 16 NVM bits (or 32 NVM bits) are software programmable through the corresponding EFC
User Interface. The command “Set Lock Bit” enables the protection. The command “Clear Lock
Bit” unlocks the lock region.
Asserting the ERASE pin clears the lock bits, thus unlocking the entire Flash.
8.8.3.2
AT91SAM7S256
The Embedded Flash Controller manages 16 lock bits to protect 16 regions of the flash against
inadvertent flash erasing or programming commands. The AT91SAM7S256 contains 16 lock
regions and each lock region contains 64 pages of 256 bytes. Each lock region has a size of 16
Kbytes.
If a locked-region’s erase or program command occurs, the command is aborted and the
LOCKE bit in the MC_FSR register rises and the interrupt line rises if the LOCKE bit has been
written at 1 in the MC_FMR register.
The 16 NVM bits are software programmable through the EFC User Interface. The command
“Set Lock Bit” enables the protection. The command “Clear Lock Bit” unlocks the lock region.
Asserting the ERASE pin clears the lock bits, thus unlocking the entire Flash.
8.8.3.3
AT91SAM7S128
The Embedded Flash Controller manages 8 lock bits to protect 8 regions of the flash against
inadvertent flash erasing or programming commands. The AT91SAM7S128 contains 8 lock
regions and each lock region contains 64 pages of 256 bytes. Each lock region has a size of 16
Kbytes.
If a locked-region’s erase or program command occurs, the command is aborted and the
LOCKE bit in the MC_FSR register rises and the interrupt line rises if the LOCKE bit has been
written at 1 in the MC_FMR register.
The 8 NVM bits are software programmable through the EFC User Interface. The command “Set
Lock Bit” enables the protection. The command “Clear Lock Bit” unlocks the lock region.
Asserting the ERASE pin clears the lock bits, thus unlocking the entire Flash.
8.8.3.4
AT91SAM7S64
The Embedded Flash Controller manages 16 lock bits to protect 16 regions of the flash against
inadvertent flash erasing or programming commands. The AT91SAM7S64 contains 16 lock
regions and each lock region contains 32 pages of 128 bytes. Each lock region has a size of 4
Kbytes.