NAND08GAH0A NUMONYX [Numonyx B.V], NAND08GAH0A Datasheet - Page 41

• Manufacturer Part Number: NAND08GAH0A
• Manufacturer: NUMONYX [Numonyx B.V]

NAND08GAH0A, NAND16GAH0D
5.5.5
5.5.6
Performing a Forced Erase
If the user forgets the password, it is possible to erase all the device data along with the
PWD content. This operation is called a Forced Erase.
The following steps are required to perform a Forced Erase operation on the device:
1.
2.
3.
An attempt to force erase on an unlocked device will fail and LOCK_UNLOCK_FAILED error
bit will be set in the Status Register.
Issuing a Forced Erase command on a permanently-write-protected device will fail, the
device will remain locked, and the LOCK_UNLOCK_FAILED error bit will be set.
The Forced Erase timeout is specified in
Application specific commands
The NAND08GAH0A and NAND16GAH0D devices support two application specific
commands:
●
●
APP_CMD command (CMD55)
Receiving a CMD55 command from the host causes the device to interpret the next
command as an application specific command, ACMD. The ACMD command has the same
structure as a regular MultiMediaCard standard commands and may have the same CMD
number. The device recognizes it as an application specific command because it follows the
APP_CMD command.
If the application specific version of the command that follows the APP_CMD command is
supported, the non standard version is used. If it is not supported, the standard version is
used.
Let us take the example of a device accepting ACMD13 but not ACMD7. When receiving the
APP_CMD command immediately followed by command 13, the device will interpret it as
the non standard command ACMD13. Whereas it will interpret command 7 as the standard
command CMD7.
Select the device if it has not been not previously selected. This is performed by issuing
a CMD7 command.
Configure the block length to 1 byte (8-bit Lock/unlock command) by issuing a CMD16
command.
Send the Lock/Unlock command on the data line, along with the data block of the
appropriate size and 16- bit CRC. The data block indicates the ERASE mode (the
ERASE bit must be the only bit set to ‘1’). The whole memory content is then erased
including the password (PWD) and PWD_LEN register, and the locked device is
unlocked. In addition, if the device was temporary write protected, it is unprotected
(write enabled), and the CSD temporary-write-protect bit and all Write-Protect-Groups
are cleared. If other bits than the ERASE bit are set to ‘1’, the
LOCK_UNLOCK_FAILED error bit is set and the Forced Erase operation fails.
APP_CMD (CMD55)
GEN_CMD (CMD56)
Table
16.
High speed MultiMediaCard operation
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