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. To start the operation, an 8-bit opcode, 88H for buffer 1 or
89H for buffer 2, must be followed by the four reserved bits, 11 address bits
(PA10 - PA0) that specify the page in the main memory to be written, and nine addi-
tional 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. 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.
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 four reserved bits,
11 address bits (PA10 - PA0), and nine don’t care bits. The 11 address bits are used to
specify 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 to 1s. The erase operation is
internally self-timed and should take place in a maximum time of tPE. During this time,
the status register 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 four
reserved bits, eight address bits (PA10 - PA3), and 12 don’t care bits. The eight 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 to
1s. The erase operation is internally self-timed and should take place in a maximum
time of tBE. During this time, the status register will indicate that the part is busy.
Block Erase Addressing
PA10
PA9
PA8
PA7
PA6
0
PA5
0
PA4
0
PA3
0
PA2
X
PA1
X
PA0
X
Block
0
0
0
0
0
0
0
0
1
2
3
0
0
0
0
0
0
1
X
X
X
0
0
0
0
0
1
0
X
X
X
0
0
0
0
0
1
1
X
X
X
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
1
1
0
1
0
1
X
X
X
X
X
X
X
X
X
X
X
X
252
253
254
255
6
AT45DB041B
1938F–DFLSH–10/02
ATMEL [ ATMEL ]
