at45db021d-ssh-sl955 ATMEL Corporation, at45db021d-ssh-sl955 Datasheet - Page 8

• Manufacturer Part Number: at45db021d-ssh-sl955
• Description: 2-megabit 2.7-volt Minimum Dataflash
• Manufacturer: ATMEL Corporation

7.3
7.4
7.5
8
Buffer to Main Memory Page Program without Built-in Erase
Page Erase
Block Erase
AT45DB021D
the part will first erase the selected page in main memory (the erased state is a logic 1) and then
program the data stored in the buffer into the specified page in main memory. Both the erase
and the programming of the page are internally self-timed and should take place in a maximum
time of t
A previously-erased page within main memory can be programmed with the contents of the
buffer. A 1-byte opcode, 88H, must be clocked into the device. For the DataFlash standard page
size (264 bytes), the opcode must be followed by three address bytes consist of 5 don’t care
bits, 10 page address bits (PA9 - PA0) that specify the page in the main memory to be written
and 9 don’t care bits. To perform a buffer to main memory page program without built-in erase
for the binary page size (256 bytes), the opcode 88H must be clocked into the device followed
by three address bytes consisting of 6 don’t care bits, 10 page address bits (A17 - A8) that spec-
ify the page in the main memory to be written and 8 don’t care bits. When a low-to-high transition
occurs on the CS pin, the part will program the data stored in the buffer into the specified page in
the main memory. It is necessary that the page in main memory that is being programmed has
been previously erased using one of the erase commands (Page Erase or Block Erase). The
programming of the page is internally self-timed and should take place in a maximum time of t
During this time, the status register will indicate that the part is busy.
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 5 don’t care bits, 10 page address
bits (PA9 - PA0) that specify the page in the main memory to be erased and 9 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 6 don’t care bits, 10 page address bits
(A17 - A8) that specify the page in the main memory to be erased and 8 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 maxi-
mum time of t
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 5 don’t care bits,
7 page address bits (PA9 -PA3) and 12 don’t care bits. The 7 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 6 don’t care bits, 7 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
this time, the status register will indicate that the part is busy.
EP
. During this time, the status register will indicate that the part is busy.
PE
. During this time, the status register will indicate that the part is busy.
3638F–DFLASH–4/08
BE
. During
P
.