SAM4L Datasheet, PDF (265/1185 Pages) ATMEL Corporation – ATSAM ARM-based Flash MCU

ATSAM4L4/L2
The page buffer is also used for writes to the User page.
Page buffer write operations are performed with 4 wait states. Any accesses attempted to the
FLASHCALW on the HSB bus during these cycles will be automatically stalled.
Writing to the page buffer can only change page buffer bits from one to zero, i.e. writing
0xAAAAAAAA to a page buffer location that has the value 0x00000000 will not change the page
buffer value. The only way to change a bit from zero to one is to erase the entire page buffer with
the Clear Page Buffer command.
The page buffer is not automatically reset after a page write. The user should do this manually
by issuing the Clear Page Buffer flash command. This can be done after a page write, or before
the page buffer is loaded with data to be stored to the flash page.
42023C–SAM–02/2013
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