AT45DB642D_14 Datasheet, PDF (11/57 Pages) List of Unclassifed Manufacturers – 64-megabit 2.7V Dual-interface DataFlash

AT45DB642D
7.6 Sector Erase
The Sector Erase command can be used to individually erase any sector in the main memory.
There are 32 sectors and only one sector can be erased at one time. To perform sector 0a or
sector 0b erase for the standard DataFlash page size (1056-bytes), an opcode of 7CH must be
loaded into the device, followed by three address bytes comprised of 10 page address bits
(PA12 - PA3) and 14 don’t care bits. To perform a sector 1-31 erase, the opcode 7CH must be
loaded into the device, followed by three address bytes comprised of five page address bits
(PA12 - PA8) and 19 don’t care bits. To perform sector 0a or sector 0b erase for the binary page
size (1024-bytes), an opcode of 7CH must be loaded into the device, followed by three address
bytes comprised of one don’t care bit and 10 page address bits (A22 - A13) and 13 don’t care
bits. To perform a sector 1-31 erase, the opcode 7CH must be loaded into the device, followed
by three address bytes comprised of one don’t care bit and five page address bits (PA12 - PA8)
and 18 don’t care bits. The page address bits are used to specify any valid address location
within the sector which is to be erased. When a low-to-high transition occurs on the CS pin, the
part will erase the selected sector. The erase operation is internally self-timed and should take
place in a maximum time of t_SE. During this time, the status register and the RDY/BUSY pin will
indicate that the part is busy.
Table 7-2. Sector Erase Addressing
PA12/
A22
0
0
0
0
•
•
•
1
1
1
1
PA11/
A21
0
0
0
0
•
•
•
1
1
1
1
PA10/
A20
0
0
0
0
•
•
•
1
1
1
1
PA9/
A19
0
0
0
1
•
•
•
0
0
1
1
PA8/
A18
0
0
1
0
•
•
•
0
1
0
1
PA7/
A17
0
0
X
X
•
•
•
X
X
X
X
PA6/
A16
0
0
X
X
•
•
•
X
X
X
X
PA5/
A15
0
0
X
X
•
•
•
X
X
X
X
PA4/
A14
0
0
X
X
•
•
•
X
X
X
X
PA3/
A13
0
1
X
X
•
•
•
X
X
X
X
PA2/
A12
X
X
X
X
•
•
•
X
X
X
X
PA1/
A11
X
X
X
X
•
•
•
X
X
X
X
PA0/
A10
X
X
X
X
•
•
•
X
X
X
X
Sector
0a
0b
1
2
•
•
•
28
29
30
31
7.7 Chip Erase⁽¹⁾
The entire main memory can be erased at one time by using the Chip Erase command.
To execute the Chip Erase command, a 4-byte command sequence C7H, 94H, 80H and 9AH
must be clocked into the device. Since the entire memory array is to be erased, no address
bytes need to be clocked into the device, and any data clocked in after the opcode will be
ignored. After the last bit of the opcode sequence has been clocked in, the CS pin can be deas-
serted to start the erase process. The erase operation is internally self-timed and should take
place in a time of t_CE. During this time, the Status Register will indicate that the device is busy.
The Chip Erase command will not affect sectors that are protected or locked down; the contents
of those sectors will remain unchanged. Only those sectors that are not protected or locked
down will be erased.
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3542N–DFLASH–2/2014