LHF16KA7 View Datasheet(PDF) - Sharp Electronics
Part Name
Description
MFG CO.
'LHF16KA7' PDF : 53 Pages View PDF
SHARP
LHF16KA7
47
Flash memory LHFXKXX family Data Protection
Noises having a level exceeding the limit specified in the specification may be
generated under specific operating conditions on some systems.
Such noises, when induced onto WE# signal or power supply, may be interpreted as false
commands, causing undesired memory updating.
To protect the data stored in the flash memory against unwanted overwriting, systems
operating with the flash memory should have the following write protect designs, as
appropriate:
1) Protecting data in specific block
Setting the lock bit of the desired block and pulling WP# low disables the writing
operation on that block. By using this feature, the flash memory space can be divided
into, for example, the program section(locked section) and data section(unlocked
set t ion).
By controlling WP#, desired blocks can be locked/unlocked through the software.
For further information on setting/resetting
block bit, refer to the specification.
(See chapter 4.12 and 4.13.)
2) Data protection through Vpp
When the level of Vpp is lower than VPPLK (lockout voltage), write operation on the
flashmemory is disabled. All blocks are lockedandthedata intheblocksarecompletely
write protected. ..’
For the l&kout voltage, refer to the specification. (See chapter 6.2.3. >
3) Data protection through RP#
When the RP# is kept low during power up and power down sequence such as voltage
transition, write operation on the flash memory is disabled, write protecting all
blocks.
For the detai 1s of RP# control, refer to the specification. (See chapter 5.6 and 6.27. )
Rev 1.9
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