LH28F008SCL-12 View Datasheet(PDF) - Sharp Electronics

Part Name

Description

Manufacturer

LH28F008SCL-12

Flash Memory 8M (1M ×8)

Sharp Electronics 

SHARP

LHF08CH3

47

Flash memoryLHFXXCXX 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 WEBsignal or power supply, maybe interpreted as false

commands, causing undesired memory updating.

To protect the data stored in the flash memoryagainst unwanted overwriting, systems

operating with the flash memoryshould have the following write protect designs, as

appropriate:

1) Protecting data in specific block

Whena lock bit is set, the corresponding block is protected against overwriting. By

using this feature, the flash memory space can be divided into the program

section(locked section) and data section(unlocked section). The master lock bit can

be used to prevent false block bit setting.

By controlling RP$, desired blocks can be locked/unlocked through the software.

For further information on setting/resetting block bit and controlling of IQ’%,refer

to the speci f icat ion. (See chapter 4.9 and 4.10)

2) Data protection through Vpp

Whenthe level of Vpp is lower than VPPLK(lockout voltage), write operation on the

flashmemory is disabled. Allblocksare lockedandthedata intheblocksarecompletely

write protected.

For the Iockout 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 details of RP#control, refer to the specifi cat ion. (See chapter 5.6 and 6.27. >

Rev 1.3

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