AT45DB021D-SSH-B-RET Atmel, AT45DB021D-SSH-B-RET Datasheet - Page 42

• Manufacturer Part Number: AT45DB021D-SSH-B-RET
• Manufacturer: Atmel

42
Figure 20-2. Algorithm for Randomly Modifying Data
Notes:
Atmel AT45DB021D
1. To preserve data integrity, each page of an Atmel DataFlash sector must be updated/rewritten at least once within
2. A Page Address Pointer must be maintained to indicate which page is to be rewritten. The Auto Page Rewrite com-
3. Other algorithms can be used to rewrite portions of the Flash array. Low-power applications may choose to wait
MAIN MEMORY PAGE PROGRAM
every 10,000 cumulative page erase and program operations
mand must use the address specified by the Page Address Pointer
until 10,000 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
THROUGH BUFFER
(82H)
AUTO PAGE REWRITE
TO BUFFER TRANSFER
ADDRESS POINTER
MAIN MEMORY PAGE
INCREMENT PAGE
START
(53H)
(58H)
END
provide address of
page to modify
MEMORY PAGE PROGRAM
(2)
(2)
BUFFER TO MAIN
BUFFER WRITE
(84H)
(83H)
If planning to modify multiple
bytes currently stored within
a page of the Flash array
3638J–DFLASH–5/10