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AT45DB641E
DS-45DB641E-027J–DFLASH–8/2017
When a low-to-high transition occurs on the CS pin, the device will program the data stored in the appropriate buffer into
the specified page in the main memory. The page in main memory that is being programmed must have been previously
erased using one of the erase commands (Page Erase, Block Erase, Sector Erase, or Chip Erase). The programming of
the page is internally self-timed and should take place in a maximum time of tP. During this time, the RDY/BUSY bit in the
Status Register will indicate that the device is busy.
The device also incorporates an intelligent programming algorithm that can detect when a byte location fails to program
properly. If a programming error arises, it will be indicated by the EPE bit in the Status Register.
6.4 Main Memory Page Program through Buffer with Built-In Erase
The Main Memory Page Program through Buffer with Built-In Erase command combines the Buffer Write and Buffer to
Main Memory Page Program with Built-In Erase operations into a single operation to help simplify application firmware
development. With the Main Memory Page Program through Buffer with Built-In Erase command, data is first clocked
into either Buffer 1 or Buffer 2, the addressed page in memory is then automatically erased, and then the contents of the
appropriate buffer are programmed into the just-erased main memory page.
To perform a Main Memory Page Program through Buffer using the standard DataFlash page size (264 bytes), an
opcode of 82h for Buffer 1 or 85h for Buffer 2 must first be clocked into the device followed by three address bytes
comprised of 15 page address bits (PA14 - PA0) that specify the page in the main memory to be written, and 9 buffer
address bits (BFA8 - BFA0) that select the first byte in the buffer to be written.
To perform a Main Memory Page Program through Buffer using the binary page size (256 bytes), an opcode of 82h for
Buffer 1 or 85h for Buffer 2 must first be clocked into the device followed by three address bytes comprised of 1 dummy
bit, 15 page address bits (A22 - A8) that specify the page in the main memory to be written, and 8 buffer address bits
(BFA7 - BFA0) that select the first byte in the buffer to be written.
After all address bytes have been clocked in, the device will take data from the input pin (SI) and store it in the specified
data buffer. 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 device 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 that main memory page. Both the erasing and the
programming of the page are internally self-timed and should take place in a maximum time of tEP. During this time, the
RDY/BUSY bit in the Status Register will indicate that the device is busy.
The device also incorporates an intelligent erase and programming algorithm that can detect when a byte location fails to
erase or program properly. If an erase or program error arises, it will be indicated by the EPE bit in the Status Register.
6.5 Main Memory Byte/Page Program through Buffer 1 without Built-In Erase
The Main Memory Byte/Page Program through Buffer 1 without Built-In Erase command combines both the Buffer Write
and Buffer to Main Memory Program without Built-In Erase operations to allow any number of bytes (1 to 256/264 bytes)
to be programmed directly into previously erased locations in the main memory array. With the Main Memory Byte/Page
Program through Buffer 1 without Built-In Erase command, data is first clocked into Buffer 1, and then only the bytes
clocked into the buffer are programmed into the pre-erased byte locations in main memory. Multiple bytes up to the page
size can be entered with one command sequence.
To perform a Main Memory Byte/Page Program through Buffer 1 using the standard DataFlash page size (264 bytes), an
opcode of 02h must first be clocked into the device followed by three address bytes comprised of 15 page address bits
(PA14 - PA0) that specify the page in the main memory to be written, and 9 buffer address bits (BFA8 - BFA0) that select
the first byte in the buffer to be written. After all address bytes are clocked in, the device will take data from the input pin
(SI) and store it in Buffer 1. Any number of bytes (1 to 264) can be entered. If the end of the buffer is reached, then the
device will wrap around back to the beginning of the buffer.
To perform a Main Memory Byte/Page Program through Buffer 1 using the binary page size (256 bytes), an opcode of
02h for Buffer 1 using must first be clocked into the device followed by three address bytes comprised of 1 dummy bit, 15
page address bits (A22 - A8) that specify the page in the main memory to be written, and 8 buffer address bits (BFA7 -
BFA0) that selects the first byte in the buffer to be written. After all address bytes are clocked in, the device will take data
from the input pin (SI) and store it in Buffer 1. Any number of bytes (1 to 256) can be entered. If the end of the buffer is