at45db041b ATMEL Corporation, at45db041b Datasheet - Page 28

• Manufacturer Part Number: at45db041b
• Description: At45db041b 4-megabit 2.5-volt Or 2.7-volt Dataflash
• Manufacturer: ATMEL Corporation

Figure 17-2. Algorithm for Randomly Modifying Data
Notes:
Table 17-1.
28
PA10
0
0
0
0
1
1
1. To preserve data integrity, each page of a DataFlash sector must be updated/rewritten at least once within every 10,000
2. A Page Address Pointer must be maintained to indicate which page is to be rewritten. The Auto Page Rewrite command
3. Other algorithms can be used to rewrite portions of the Flash array. Low-power applications may choose to wait until 10,000
AT45DB041B
cumulative page erase/program operations.
must use the address specified by the Page Address Pointer.
cumulative page erase/program operations have accumulated before rewriting all pages of the sector. See application note
AN-4 (“Using Atmel’s Serial DataFlash”) for more details.
Sector Addressing
PA9
0
0
0
1
0
1
MAIN MEMORY PAGE PROGRAM
PA8
X
X
X
0
0
1
THROUGH BUFFER
(82H, 85H)
PA7
X
X
X
X
X
0
AUTO PAGE REWRITE
TO BUFFER TRANSFER
ADDRESS POINTER
MAIN MEMORY PAGE
INCREMENT PAGE
PA6
X
X
X
X
X
0
(53H, 55H)
(58H, 59H)
START
END
provide address of
page to modify
MEMORY PAGE PROGRAM
PA5
(2)
X
X
X
X
X
0
(2)
BUFFER TO MAIN
BUFFER WRITE
(84H, 87H)
(83H, 86H)
PA4
X
X
X
X
X
0
If planning to modify multiple
bytes currently stored within
a page of the Flash array
PA3
X
X
X
X
X
0
PA2 - PA0
X
X
X
X
X
X
3443D–DFLSH–2/08
Sector
0
1
2
3
4
5