5 block erase, 6 sector erase, 4 page erase – Rainbow Electronics AT45DB021D User Manual
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3638K–DFLASH–11/2012
AT45DB021D
5.4
Page Erase
The Page Erase command can be used to individually erase any page in the main memory array allowing the
Buffer to Main Memory Page Program to be utilized at a later time. To perform a page erase in the DataFlash
standard page size (264-bytes), an opcode of 81H must be loaded into the device, followed by three address bytes
comprised of five don’t care bits, 10 page address bits (PA9 - PA0) that specify the page in the main memory to be
erased and nine don’t care bits. To perform a page erase in the binary page size (256-bytes), the opcode 81H must
be loaded into the device, followed by three address bytes consist of six don’t care bits, 10 page address bits (A17
- A8) that specify the page in the main memory to be erased and eight don’t care bits. When a low-to-high transition
occurs on the CS pin, the part will erase the selected page (the erased state is a logical 1). The erase operation is
internally self-timed and should take place in a maximum time of t
PE
. During this time, the status register will
indicate that the part is busy.
5.5
Block Erase
A block of eight pages can be erased at one time. This command is useful when large amounts of data has to be
written into the device. This will avoid using multiple Page Erase Commands. To perform a block erase for the
DataFlash standard page size (264-bytes), an opcode of 50H must be loaded into the device, followed by three
address bytes comprised of five don’t care bits, seven page address bits (PA9 -PA3) and 12 don’t care bits. The
seven page address bits are used to specify which block of eight pages is to be erased. To perform a block erase
for the binary page size (256-bytes), the opcode 50H must be loaded into the device, followed by three address
bytes consisting of six don’t care bits, seven page address bits (A17 - A11) and 11 don’t care bits. The 9-page
address bits are used to specify which block of eight pages is to be erased. When a low-to-high transition occurs
on the CS pin, the part will erase the selected block of eight pages. The erase operation is internally self-timed and
should take place in a maximum time of t
BE
. During this time, the status register will indicate that the part is busy.
Table 5-1.
Block Erase Addressing
5.6
Sector Erase
The Sector Erase command can be used to individually erase any sector in the main memory. There are four
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 (264-bytes), an opcode of 7CH must be loaded into the device, followed by three address bytes
comprised of five don’t care bits, seven page address bits (PA9 - PA3) and 12 don’t care bits. To perform a sector
1-7 erase, the opcode 7CH must be loaded into the device, followed by three address bytes comprised of five don’t
care bits, three page address bits (PA9 - PA7) and 16 don’t care bits. To perform sector 0a or sector 0b erase for
PA9/
A17
PA8/
A16
PA7/
A15
PA6/
A14
PA5/
A13
PA4/
A12
PA3/
A11
PA2/
A10
PA1/
A9
PA0/
A8
Block
0
0
0
0
0
0
0
X
X
X
0
0
0
0
0
0
0
1
X
X
X
1
0
0
0
0
0
1
0
X
X
X
2
0
0
0
0
0
1
1
X
X
X
3
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
1
1
1
1
1
0
0
X
X
X
124
1
1
1
1
1
0
1
X
X
X
125
1
1
1
1
1
1
0
X
X
X
126
1
1
1
1
1
1
1
X
X
X
127