AT45DB321C datasheet(6/37 Pages) ATMEL

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AT45DB321C [Preliminary]

3387B–DFLSH–9/04

MAIN MEMORY PAGE PROGRAM THROUGH BUFFER: This operation is a combina-

tion of the Buffer Write and Buffer to Main Memory Page Program with Built-in Erase

operations. Data is first clocked into buffer 1 or buffer 2 from the input pin (SI) and then

programmed into a specified page in the main memory. To initiate the operation, an 8-bit

opcode, 82H for buffer 1 or 85H for buffer 2, must first be clocked into the device, fol-

lowed by three address bytes. The address bytes are comprised of one reserved bit, 13

page address bits (PA12-PA0) that select the page in the main memory where data is to

be written, and 10 buffer address bits (BFA9-BFA0) that select the first byte in the buffer

to be written. After all address bytes are clocked in, the part will take data from the input

pins 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 part will first erase the selected page in main memory to all

1s and then program the data stored in the buffer into that memory page. 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.

Additional Commands

MAIN MEMORY PAGE TO BUFFER TRANSFER: A page of data can be transferred

from the main memory to either buffer 1 or buffer 2. To start the operation, a 1-byte

opcode, 53H for buffer 1 and 55H for buffer 2, must be clocked into the device, followed

by three address bytes comprised of one reserved bit, 13 page address bits (PA12-

PA0), which specify the page in main memory that is to be transferred, and 10 don’t care

bits. The CS pin must be low while toggling the SCK pin to load the opcode and the

address bytes from the input pin (SI). 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

XFR), the status register can be read or the

RDY/BUSY can be monitored to determine whether the transfer has been completed.

AUTO PAGE REWRITE: This mode is only needed if multiple bytes within a page or

multiple pages of data are modified in a random fashion. This mode is a combination of

two operations: Main Memory Page to Buffer Transfer and Buffer to Main Memory Page

Program with Built-in Erase. A page of data is first transferred from the main memory to

buffer 1 or buffer 2, and then the same data (from buffer 1 or buffer 2) is programmed

back into its original page of main memory. To start the rewrite operation, a 1-byte

opcode, 58H for buffer 1 or 59H for buffer 2, must be clocked into the device, followed

by three address bytes comprised of one reserved bit, 13 page address bits (PA12-PA0)

Block Erase Addressing

PA12

PA11

PA10

PA9

PA8

PA7

PA6

PA5

PA4

PA3

PA2

PA1

PA0

Block

000

•

111

1020

111

1021

111

1022

111

1023

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