M29DW128G70NF6E NUMONYX, M29DW128G70NF6E Datasheet - Page 21

• Manufacturer Part Number: M29DW128G70NF6E
• Description: P7ED TSOP56 DUAL BANK
• Manufacturer: NUMONYX

M29DW128G
6.1
6.2
6.2.1
If the user attempts to program or erase a protected block, the device ignores the command
and returns to read mode.
The device is shipped with all blocks unprotected. The block protection status can be read
either by performing a read electronic signature (see
by issuing an Auto Select command (see
For the four outermost blocks (that is the two blocks at the top and the two at the bottom of
the address space), an even higher level of block protection can be achieved by locking the
blocks using the non-volatile protection and then by holding the V
Volatile protection mode
The volatile protection allows the software application to easily protect blocks against
inadvertent change. However, the protection can be easily disabled when changes are
needed. Volatile protection bits, VPBs, are volatile and unique for each block and can be
individually modified. VPBs only control the protection scheme for unprotected blocks that
have their non-volatile protection bits, NVPBs, cleared (erased to ‘1’) (see
volatile protection mode
By issuing the VPB Program or VPB Clear commands, the VPBs are set (programmed to
‘0’) or cleared (erased to ‘1’), thus placing each block in the protected or unprotected state
respectively. The VPBs can be set (programmed to ‘0’) or cleared (erased to ‘1’) as often as
needed.
The default values of the volatile protections are set through the VLBB (volatile lock boot bit)
of the lock register (see
When the parts are first shipped, or after a power-up or hardware reset, the VPBs can be
set or cleared depending upon the ordering option chosen:
Refer to
Non-volatile protection mode
Non-volatile protection bits
A non-volatile protection bit (NVPB) is assigned to each block.
When a NVPB is set to ‘0’, the associated block is protected, preventing any program or
erase operations in this block.
The NVPB bits are set individually by issuing a NVPB Program command. They are non-
volatile and will remain set through a hardware reset or a power-down/power-up sequence.
The NVPBs cannot be cleared individually, they can only be cleared all at the same time by
issuing a Clear all Non-volatile Protection Bits command.
The NVPBs can be protected all at a time by setting a volatile bit, the NVPB lock bit (see
Section 6.2.2: Non-volatile protection bit lock
If the option to clear the VPBs after power-up is selected, then the blocks can be
programmed or erased depending on the NVPBs state (see
status)
If the option to set the VPBs after power-up is selected, the blocks default to be
protected.
Section 7.3.7
for a description of the volatile protection mode command set.
Table 13: Lock register
and
Section 7.3.5: Non-volatile protection mode command
Table 14: Block protection
bit).
bits).
Table 5: Read electronic
PP
Table 14: Block protection
/WP pin Low.
status).
Software protection
Section 6.2: Non-
signature) or
set).
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