AT45D041-JI ATMEL [ATMEL Corporation], AT45D041-JI Datasheet - Page 3
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AT45D041-JI
Manufacturer Part Number
AT45D041-JI
Description
4-Megabit 5-volt Only Serial DataFlash
Manufacturer
ATMEL [ATMEL Corporation]
Datasheet
1.AT45D041-JI.pdf
(16 pages)
buffer 2. To perform a buffer read, the eight bits of the
opcode must be followed by 15 don’t care bits, nine
address bits, and eight don't care bits. Since the buffer size
is 264-bytes, nine address bits (BFA8-BFA0) are required
to specify the first byte of data to be read from the buffer.
The CS pin must remain low during the loading of the
opcode, the address bits, the don’t care bits, and the read-
ing of data. When the end of a buffer is reached, the device
will continue reading back at the beginning of the buffer. A
low to high transition on the CS pin will terminate the read
operation and tri-state the SO pin.
MAIN MEMORY PAGE TO BUFFER TRANSFER: A page
of data can be transferred from the main memory to either
buffer 1 or buffer 2. An 8-bit opcode, 53H for buffer 1 and
55H for buffer 2, is followed by the four reserved bits, 11
address bits (PA10-PA0) which specify the page in 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 transitions
from a low to a high state. During the transfer of a page of
data (t
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
buffer 1 or buffer 2. An 8-bit opcode, 60H for buffer 1 and
61H for buffer 2, is followed by 24 address bits consisting of
the four reserved bits, 11 address bits (PA10-PA0) which
specify the page in the main memory that is to be com-
pared 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 toggling 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 transition of the CS
pin, the 264 bytes in the selected main memory page will
be compared with the 264 bytes in buffer 1 or buffer 2. Dur-
ing this time (t
part is busy. On completion of the compare operation, bit 6
of the status register is updated with the result of the com-
pare.
Program
BUFFER WRITE: Data can be shifted in from the SI pin
into either buffer 1 or buffer 2. To load data into either
buffer, an 8-bit opcode, 84H for buffer 1 or 87H for buffer 2,
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.
XFR
), the status register can be read to determine
XFR
), the status register will indicate that the
BUFFER TO MAIN MEMORY PAGE PROGRAM WITH
BUILT-IN ERASE: Data written into either buffer 1 or buffer
2 can be programmed into the main memory. An 8-bit
opcode, 83H for buffer 1 or 86H for buffer 2, is followed by
the four reserved bits, 11 address bits (PA10-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 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 page
are internally self timed and should take place in a maxi-
mum time of t
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
either buffer 1 or buffer 2. An 8-bit opcode, 88H for buffer 1
or 89H for buffer 2, is followed by the four reserved bits, 11
address bits (PA10-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 previ-
ously programmed to all 1s (erased state). The program-
ming of the page is internally self timed and should take
place in a maximum time of t
register will indicate that the part is busy.
MAIN MEMORY PAGE PROGRAM: This operation is a
combination of the Buffer Write and Buffer to Main Memory
Page Program with Built-In Erase operations. Data is first
shifted into buffer 1 or buffer 2 from the SI pin and then pro-
grammed into a specified page in the main memory. An 8-
bit opcode, 82H for buffer 1 or 85H for buffer 2, is followed
by the four reserved bits and 20 address bits. The 11 most
significant address bits (PA10-PA0) select the page in the
main memory where data is to be written, and the next nine
address bits (BFA8-BFA0) select the first byte in the buffer
to be written. After all address bits are shifted in, the part
will take data from the SI pin and store it in one of the data
buffers. If the end of the buffer is reached, the device will
wrap around back to the beginning of the buffer. When
there is a low to high transition 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 program-
ming of the page are internally self timed and should take
place in a maximum of time t
register will indicate that the part is busy.
AUTO PAGE REWRITE: This mode is only needed if multi-
ple bytes within a page or multiple pages of data are modi-
fied in a random fashion. This mode is a combination of two
operations: Main Memory Page to Buffer Transfer and
EP
. During this time, the status register will
EP
P
. During this time, the status
. During this time, the status
3