7. Program and Erase Commands
7.1
Buffer Write
Data can be clocked in from the input pin (SI) into either buffer 1 or buffer 2. To load data into the
standard DataFlash buffer (264-bytes), a 1-byte opcode, 84H for buffer 1 or 87H for buffer 2,
must be clocked into the device, followed by three address bytes comprised of 15 don’t care bits
and nine buffer address bits (BFA8 - BFA0). The nine buffer address bits specify the first byte in
the buffer to be written. To load data into the binary buffers (256-bytes each), a 1-byte opcode
84H for buffer 1 or 87H for buffer 2, must be clocked into the device, followed by three address
bytes comprised of 16 don’t care bits and eight buffer address bits (BFA7 - BFA0). The eight buf-
fer address bits specify the first byte in the buffer to be written. After the last address byte has
been clocked into the device, data can then be clocked in on subsequent clock cycles. 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.
7.2
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. For the DataFlash
standard page size (264-bytes), the opcode must be followed by three address bytes consist of
three don’t care bits, 12 page address bits (PA11 - PA0) that specify the page in the main mem-
ory to be written and nine don’t care bits. To perform a buffer to main memory page program
with built-in erase for the binary page size (256-bytes), the opcode 83H for buffer 1 or 86H for
buffer 2, must be clocked into the device followed by three address bytes consisting of four don’t
care bits 12 page address bits (A19 - A8) that specify the page in the main memory to be written
and eight 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 logic 1) and then program the
data stored in the buffer into the specified page in main memory. Both the erase and the pro-
gramming of the page are internally self-timed and should take place in a maximum time of tEP.
During this time, the status register will indicate that the part is busy.
7.3
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. For the DataFlash standard page size (264-bytes), the opcode must be followed by
three address bytes consist of three don’t care bits, 12 page address bits (PA11 - PA0) that
specify the page in the main memory to be written and nine 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 for buffer 1 or 89H for buffer 2, must be clocked into the device followed by three
address bytes consisting of four don’t care bits, 12 page address bits (A19 - A8) that specify the
page in the main memory to be written and eight 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 tP.
During this time, the status register will indicate that the part is busy.
8
AT45DB081D
3596O–DFLASH–1/2013
ADI [ ADI ]
