AT45DB321D ATMEL [ATMEL Corporation], AT45DB321D Datasheet - Page 46

• Manufacturer Part Number: AT45DB321D
• Description: 32-megabit 2.7-volt DataFlash
• Manufacturer: ATMEL [ATMEL Corporation]

Figure 25-2. Algorithm for Randomly Modifying Data
Notes:
46
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
AT45DB321D
cumulative page erase and program operations.
must use the address specified by the Page Address Pointer.
cumulative page erase and program operations have accumulated before rewriting all pages of the sector. See application
note AN-4 (“Using Atmel’s Serial DataFlash”) for more details.
MAIN MEMORY PAGE PROGRAM
THROUGH BUFFER
(82H, 85H)
AUTO PAGE REWRITE
TO BUFFER TRANSFER
ADDRESS POINTER
MAIN MEMORY PAGE
INCREMENT PAGE
(53H, 55H)
(58H, 59H)
START
END
provide address of
page to modify
MEMORY PAGE PROGRAM
(2)
(2)
BUFFER TO MAIN
BUFFER WRITE
(84H, 87H)
(83H, 86H)
If planning to modify multiple
bytes currently stored within
a page of the Flash array
3597J–DFLASH–4/08