28F640W30 NUMONYX [Numonyx B.V], 28F640W30 Datasheet - Page 73

• Manufacturer Part Number: 28F640W30
• Description: Numonyx Wireless Flash Memory (W30)
• Manufacturer: NUMONYX [Numonyx B.V]

Numonyx™ Wireless Flash Memory (W30)
13.1.4
Note:
Table 25: Write Protection Truth Table
13.1.5
November 2007
Order Number: 290702-13
VPP
V
X
X
X
IL
Block Lock Status
The lock status of every block can be read in read identifier mode.
To enter this mode, issue the Read Identifier command to the flash device.
Subsequent reads at BBA + 02h output the lock status of that block. For example, to
read the block lock status of block 10, the address sent to the flash device must be
50002h (for a top-parameter device).
The lowest two data bits of the read data, DQ1 and DQ0, represent the lock status.
The lock-down status bit cannot be cleared by software–only by a flash device reset or
power-down. See
Lock During Erase Suspend
Block lock configurations can be performed during an erase suspend operation, using
the standard locking command sequences to unlock, lock, or lock-down a block. This
feature is useful when another block requires immediate updating.
To change block locking during an erase operation:
If a block is locked or locked-down during a suspended erase of the same block, the
locking status bits change immediately. When the erase operation resumes, it
completes normally.
1. Write the Erase Suspend command.
2. Check SR[6] to determine that the erase operation has suspended.
3. Write the desired lock command sequence to a block.
4. After completing lock, unlock, read, or program operations, resume the erase
• To lock-down a locked or unlocked block, write the Lock-Down Block command
• If a block was set to locked-down, then later changed to unlocked, issue the Lock-
• When WP# is deasserted, locked-down blocks change to the locked state, and can
• DQ0 indicates the block lock status. This bit is set using the Lock Block command
• DQ1 indicates lock-down status and is set using the Lock-Down command.
sequence.
down command before asserting WP#, to put that block back in the locked-down
state.
then be unlocked using the Unlock Block command.
and cleared using the Block Unlock command. It is also set when entering the lock-
down state.
The lock status changes.
operation with the Erase Resume command (D0h).
WP#
V
V
X
X
IH
IL
RST#
V
V
V
V
Table
IH
IH
IH
IL
25.
Device is inaccessible
Word program and block erase are prohibited
All lock-down blocks are locked
All lock-down blocks can be unlocked
Write Protection
Datasheet
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