AT45DB ATMEL Corporation, AT45DB Datasheet - Page 4

• Manufacturer Part Number: AT45DB
• Description: 1-Megabit 2.7-volt Only Serial DataFlash
• Manufacturer: ATMEL Corporation

main memory that is to be transferred, and nine don’t care
bits. The CS pin must be low while toggling the SCK pin to
load the opcode, the address bits, and the don’t care bits
from the SI pin. The transfer of the page of data from the
main memory to the buffer will begin when the CS pin tran-
sitions from a low to a high state. During the transfer of a
page of data (t
mine whether the transfer has been completed or not.
MAIN MEMORY PAGE TO BUFFER COMPARE: A page of
data in main memory can be compared to the data in the
buffer. An 8-bit opcode of 60H is followed by 24 address
bits consisting of the six reserved bits, nine address bits
(PA8-PA0) which specify the page in the main memory that
is to be compared to the buffer, and nine don’t care bits.
The loading of the opcode and the address bits is the same
as described previously. The CS pin must be low while tog-
gling the SCK pin to load the opcode, the address bits, and
the don't care bits from the SI pin. On the low to high transi-
tion of the CS pin, the 264 bytes in the selected main mem-
ory page will be compared with the 264 bytes in the buffer.
During this time (t
the part is busy. On completion of the compare operation,
bit 6 of the status register is updated with the result of the
compare.
Program
BUFFER WRITE: Data can be shifted in from the SI pin
into the data buffer. To load data into the buffer, an 8-bit
opcode of 84H is followed by 15 don’t care bits and nine
address bits (BFA8-BFA0). The nine address bits specify
the first byte in the buffer to be written. The data is entered
following the address bits. If the end of the data buffer is
reached, the device will wrap around back to the beginning
of the buffer. Data will continue to be loaded into the buffer
until a low to high transition is detected on the CS pin.
BUFFER TO MAIN MEMORY PAGE PROGRAM WITH
BUILT-IN ERASE: Data written into the buffer can be pro-
grammed into the main memory. An 8-bit opcode of 83H is
followed by the six reserved bits, nine address bits (PA8-
PA0) that specify the page in the main memory to be writ-
ten, and nine additional don’t care bits. When a low to high
transition occurs on the CS pin, the part will first erase the
selected page in main memory to all 1s and then program
the data stored in the buffer into the specified page in the
main memory. Both the erase and the programming of the
4
XFR
), the status register can be read to deter-
XFR
), the status register will indicate that
AT45DB011
page are internally self timed and should take place in a
maximum time of t
will indicate that the part is busy.
BUFFER TO MAIN MEMORY PAGE PROGRAM WITH-
OUT BUILT-IN ERASE: A previously erased page within
main memory can be programmed with the contents of the
buffer. An 8-bit opcode of 88H is followed by the six
reserved bits, nine address bits (PA8-PA0) that specify the
page in the main memory to be written, and nine additional
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. The programming of the page
is internally self timed and should take place in a maximum
time of t
that the part is busy.
PAGE ERASE: The optional Page Erase command can be
used to individually erase any page in the main memory
array allowing the Buffer to Main Memory Page Program
without Built-In Erase command to be utilized at a later
time. To perform a Page Erase, an opcode of 81H must be
loaded into the device, followed by six reserved bits, nine
address bits (PA8-PA0), and nine don’t care bits. The nine
address bits are used to specify which page of the memory
array is to be erased. When a low to high transition occurs
on the CS pin, the part will erase the selected page to 1s.
The erase operation is internally self-timed and should take
place in a maximum time of t
register will indicate that the part is busy.
BLOCK ERASE: A block of eight pages can be erased at
one time allowing the Buffer to Main Memory Page Pro-
gram without Built-In Erase command to be utilized to
reduce programming times when writing large amounts of
data to the device. To perform a Block Erase, an opcode of
50H must be loaded into the device, followed by six
reserved bits, six address bits (PA8-PA3), and 12 don’t
care bits. The six 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 to 1s. The erase operation is
internally self-timed and should take place in a maximum
time of t
that the part is busy.
BE
P
. During this time, the status register will indicate
. During this time, the status register will indicate
EP
. During this time, the status register
PE
. During this time, the status