128Mb, 256Mb, 512Mb, 1Gb StrataFlash Memory
Erase Operations
Erase Operations
BLOCK ERASE
Erasing a block changes 0s to 1s. To change 1s to 0s, a PROGRAM operation must be
performed. Erasing is performed on a block basis; an entire block is erased each time an
erase command sequence is issued. Once a block is fully erased, all addressable loca-
tions within that block read as logical 1s (FFFFh).
Only one BLOCK ERASE operation can occur at a time. A BLOCK ERASE operation is
not permitted during program suspend. All BLOCK ERASE operations require the ad-
dressed block to be unlocked, and VPP must be at VPPL or VPPH throughout the BLOCK
ERASE operation. Otherwise, the operation aborts, setting the appropriate status regis-
ter error bit(s).
To perform a BLOCK ERASE operation, issue the BLOCK ERASE SETUP command at the
desired block address. The read mode of the addressed partition automatically changes
to read status register mode and remains in effect until another READ MODE command
is issued.
The ERASE CONFIRM command latches the address of the block to be erased. The ad-
dressed block is preconditioned (programmed to all 0s), erased, and then verified.
Issuing the READ STATUS REGISTER command to another partition switches that par-
tition’s read mode to the read status register, thereby allowing block erase progress to be
monitored from that partition’s address. SR0 indicates whether the addressed partition
or the other partition is erasing.
During a BLOCK ERASE operation, the status register indicates a busy status (SR[7] = 0).
Issuing the READ ARRAY command to a partition that is actively erasing a main block
causes subsequent reads from that partition to output invalid data. Valid array data is
output only after the BLOCK ERASE operation has finished.
Upon completion, the status register indicates a ready status (SR[7] = 1). The status reg-
ister should be checked for any errors, and then cleared.
If the device is deselected during an ERASE operation, the device continues to consume
active power until the ERASE operation is completed.
Asserting RST# immediately aborts the BLOCK ERASE operation, and array contents at
the addressed location are indeterminate. The addressed block should be erased again.
The only valid commands during a BLOCK ERASE operation are READ ARRAY, READ ID,
READ CFI, and ERASE SUSPEND. After the BLOCK ERASE operation has completed,
any valid command can be issued.
Table 23: ERASE Command Bus Cycle
Setup WRITE Cycle
Setup WRITE Cycle Confirm WRITE Cycle Confirm WRITE Cycle
Command
Address Bus
Data Bus
Address Bus
Data Bus
BLOCK ERASE
Device address
0020h
Block address
00D0h
PDF: 09005aef8448483a
128_256_512_65nm_g18.pdf - Rev. F 8/11 EN
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