M58LR128KB855 datasheet(52/110 Pages) NUMONYX

52 / 110 page

Block locking

M58LR128KT, M58LR128KB, M58LR256KT, M58LR256KB

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9.4

Lock-down state

Blocks that are locked-down (state (0,1,x))are protected from program and erase operations

(as for locked blocks) but their protection status cannot be changed using software

commands alone. A locked or unlocked block can be locked down by issuing the Lock-Down

command. Locked-down blocks revert to the locked state when the device is reset or

powered-down.

The lock-down function is dependent on the Write Protect, WP, input pin.

When WP=0 (VIL), the blocks in the lock-down state (0,1,x) are protected from program,

erase and protection status changes.

When WP=1 (VIH) the lock-down function is disabled (1,1,x) and locked-down blocks can be

individually unlocked to the (1,1,0) state by issuing the software command, where they can

be erased and programmed.

When the lock-down function is disabled (WP=1) blocks can be locked (1,1,1) and unlocked

(1,1,0) as desired. When WP=0 blocks that were previously locked-down return to the lock-

down state (0,1,x) regardless of any changes that were made while WP=1.

Device reset or power-down resets all blocks, including those in lock-down, to the locked

state.

9.5

Locking operations during erase suspend

Changes to block lock status can be performed during an erase suspend by using the

standard locking command sequences to unlock, lock or lock-down a block. This is useful in

the case when another block needs to be updated while an erase operation is in progress.

To change block locking during an erase operation, first write the Erase Suspend command,

then check the Status Register until it indicates that the erase operation has been

suspended. Next write the desired Lock command sequence to a block and the lock status

is changed. After completing any desired lock, read, or program operations, resume the

erase operation with the Erase Resume command.

If a block is locked or locked down during an erase suspend of the same block, the locking

status bits is changed immediately, but when the erase is resumed, the erase operation

completes. Locking operations cannot be performed during a program suspend.

M58LR128KB855 Datenblatt(PDF) 52 Page - Numonyx B.V