7.6
Sector Erase
The Sector Erase command can be used to individually erase any sector in the main memory.
There are 64 sectors and only one sector can be erased at one time. To perform sector 0a or
sector 0b erase for the DataFlash standard page size (528 bytes), an opcode of 7CH must be
loaded into the device, followed by three address bytes comprised of 1 don’t care bit, 10 page
address bits (PA12 - PA3) and 13 don’t care bits. To perform a sector 1-63 erase, the opcode
7CH must be loaded into the device, followed by three address bytes comprised of 1 don’t
care bit, 6 page address bits (PA12 - PA7) and 17 don’t care bits. To perform sector 0a or sector
0b erase for the binary page size (512 bytes), an opcode of 7CH must be loaded into the
device, followed by three address bytes comprised of 2 don’t care bit and 10 page address bits
(A21 - A12) and 12 don’t care bits. To perform a sector 1-63 erase, the opcode 7CH must be
loaded into the device, followed by three address bytes comprised of 2 don’t care bits and
6 page address bits (A21 - A16) and 16 don’t care bits. The page address bits are used to spec-
ify 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.
PA12/
A21
0
0
0
0
•
•
•
1
1
1
1
Sector Erase Addressing
PA10/
A19
0
0
0
0
•
•
•
1
1
1
1
PA9/
A18
0
0
0
0
•
•
•
1
1
1
1
PA8/
A17
0
0
0
1
•
•
•
0
0
1
1
PA7/
A16
0
0
1
0
•
•
•
0
1
0
1
PA6/
A15
0
0
X
X
•
•
•
X
X
X
X
PA5/
A14
0
0
X
X
•
•
•
X
X
X
X
PA4/
A13
0
0
X
X
•
•
•
X
X
X
X
PA3/
A12
0
1
X
X
•
•
•
X
X
X
X
PA2/
A11
X
X
X
X
•
•
•
X
X
X
X
PA1/
A10
X
X
X
X
•
•
•
X
X
X
X
PA0/
A9
X
X
X
X
•
•
•
X
X
X
X
Sector
0a
0b
1
2
•
•
•
60
61
62
63
PA11/
A20
0
0
0
0
•
•
•
1
1
1
1
7.7
Chip Erase
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.
Note:
1. Refer to the errata regarding Chip Erase on
10
AT45DB321D
3597N–DFLASH–04/09
ATMEL [ ATMEL CORPORATION ]
