KFM2G16Q2M-DEB5 SAMSUNG [Samsung semiconductor], KFM2G16Q2M-DEB5 Datasheet - Page 67

• Manufacturer Part Number: KFM2G16Q2M-DEB5
• Description: MuxOneNAND FLASH MEMORY
• Manufacturer: SAMSUNG [Samsung semiconductor]

MuxOneNAND1G(KFM1G16Q2M-DEB5)
MuxOneNAND2G(KFN2G16Q2M-DEB5)
3.4
The MuxOneNAND can be write-protected to prevent re-programming or erasure of data.
The areas of write-protection are the BootRAM, and the NAND Flash Array.
3.4.1
At system power-up, voltage detector in the device detects the rising edge of Vcc and releases the internal power-up reset signal
which triggers bootcode loading. And the designated size data(1KB) is copied from the first page of the first block in the NAND flash
array to the BootRAM.
After the bootcode loading is completed, the BootRAM is always locked to protect the boot code from the accidental write.
3.4.2
The device has both hardware and software write protection of the NAND Flash array.
Hardware Write Protection Operation
The hardware write protection operation is implemented by executing a Cold or Warm Reset. On power up, the NAND Flash Array is
in its default, locked state. The entire NAND Flash array goes to a locked state after a Cold or Warm Reset.
Software Write Protection Operation
The software write protection operation is implemented by writing a Lock command (002Ah) or a Lock-tight command (002Ch) to
command register (F220h).
Lock (002Ah) and Lock-tight (002Ch) commands write protects the block defined in the Start Block Address Register F24Ch.
3.4.3
There are three lock states in the NAND Array: unlocked, locked, and locked-tight.
MuxOneNAND1G supports lock/unlock/lock-tight by one block, so each block should be locked/unlocked/locked-tight individually.
Write Protection Status
The current block Write Protection status can be read in NAND Flash Write Protection Status Register(F24Eh). There are three bits -
US, LS, LTS -, which are not cleared by hot reset. These Write Protection status registers are updated when FBA is set, and when
Write Protection command is entered.
The followings summarize locking status.
example)
-> If host executes unlock block operation, then [2:0] values turn to 100.
-> If host executes lock-tight block operation, then [2:0] values turn to 001.
In default, [2:0] values are 010.
NAND Flash Array Write Protection Operation
BootRAM Write Protection Operation
NAND Array Write Protection States
Write Protection Operation
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FLASH MEMORY