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AT45DB321D [DATASHEET]

3597T–DFLASH–11/2013

5.

Program and Erase Commands

5.1

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

(528 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 14 don’t care bits and 10 buffer address bits (BFA9 - BFA0). The 10 buffer address bits specify the first byte

in the buffer to be written. To load data into the binary buffers (512 bytes each), a 1-byte 84H opcode for buffer 1 or 87H opcode

for buffer 2 must be clocked into the device, followed by three address bytes comprised of 15 don’t care bits and 9 buffer

address bits (BFA8 - BFA0). The nine buffer 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.

5.2

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 standard DataFlash page size (528 bytes), the opcode must be followed by

three address bytes consist of 1 don’t care bit, 13 page address bits (PA12 - PA0) that specify the page in the main memory to

be written, and 10 don’t care bits. To perform a buffer to main memory page program with built-in erase for the binary page size

(512 bytes), the 83H opcode for buffer 1 or 86H opcode for buffer 2 must be clocked into the device, followed by three address

bytes consisting of 2 don’t care bits, 13 page address bits (A21 - A9) that specify the page in the main memory to be written, and

9 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 one) and then program the data stored in the buffer into the specified page in main memory. The

time, the status register and the RDY/BUSY pin will indicate that the part is busy.

5.3

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 one-byte

opcode, 88H for buffer 1 or 89H for buffer 2, must be clocked into the device. For the standard DataFlash page size (528 bytes),

the opcode must be followed by three address bytes that consist of 1 don’t care bit, 13 page address bits (PA12 - PA0) that

specify the page in the main memory to be written, and 10 don’t care bits. To perform a buffer to main memory page program

without built-in erase for the binary page size (512 bytes), the 88H opcode for buffer 1 or 89H opcode for buffer 2 must be

clocked into the device, followed by three address bytes consisting of 2 don’t care bits, 13 page address bits (A21 - A9) that

specify the page in the main memory to be written, and 9 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 being programmed has been previously erased using one of the erase commands (page erase or block erase). The

register and the RDY/BUSY pin will indicate that the part is busy.

5.4

Page Erase

The page erase command can be used to individually erase any page in the main memory array, allowing the buffer to main

memory page program to be utilized at a later time. To perform a page erase in the standard DataFlash page size (528 bytes),

an opcode of 81H must be loaded into the device, followed by three address bytes comprised of 1 don’t care bit, 13 page

address bits (PA12 - PA0) that specify the page in the main memory to be erased, and 10 don’t care bits. To perform a page

erase in the binary page size (512 bytes), the 81H opcode must be loaded into the device, followed by three address bytes

consisting of 2 don’t care bits, 13 page address bits (A21 - A9) that specify the page in the main memory to be erased, and 9

don’t care bits. When a low-to-high transition occurs on the CS pin, the part will erase the selected page (the erased state is a

status register and the RDY/BUSY pin will indicate that the part is busy.