Rainbow Electronics AT45DB642 - Manual (Page 7)

7
AT45DB642
1638F–DFLSH–09/02
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. A 1-byte opcode, 83H for
buffer 1 or 86H for buffer 2, must be clocked into the device followed by three address bytes
consisting of 13 page address bits (PA12 - PA0) that specify the page in the main memory to
be written and 11 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 (the erased state is a logical 1) and then pro-
gram 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
EP
. During this time, the status register and the RDY/BUSY pin will indicate that the
part is busy.
BUFFER TO MAIN MEMORY PAGE PROGRAM WITHOUT BUILT-IN ERASE: A previously-
erased page within main memory can be programmed with the contents of either buffer 1 or
buffer 2. A 1-byte opcode, 88H for buffer 1 or 89H for buffer 2, must be clocked into the device
followed by three address bytes consisting of 13 page address bits (PA12 - PA0) that specify
the page in the main memory to be written and 11 don’t care bits. When a low-to-high transi-
tion 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 pro-
grammed has been previously erased using one of the optional 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
P
. During this time, the status register and the RDY/BUSY pin will indicate
that the part is busy.
Successive page programming operations, without doing a page erase, are not recom-
mended. In other words, changing bytes within a page from a “1” to a “0” during multiple page
programming operations without erasing that page is not recommended.
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 three address bytes comprised of 13 page
address bits (PA12 - PA0) and 11 don’t care bits. The 13 page address bits are used to spec-
ify 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 (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 and the RDY/BUSY pin 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 Program 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 three address bytes comprised of 10 page
address bits (PA12 -PA3) and 14 don’t care bits. The 10 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 and
the RDY/BUSY pin will indicate that the part is busy.