Datasheet

129
6120F–ATARM–03-Oct-06
AT91SAM7X512/256/128 Preliminary
20.3.4.1 Flash Read Command
This command is used to read the Flash contents. The memory map is accessible through this
command. Memory is seen as an array of words (32-bit wide). The read command can start at
any valid address in the memory plane. This address must be word-aligned. The address is
automatically incremented.
20.3.4.2 Flash Write Command
This command is used to write the Flash contents. The address transmitted must be a valid
Flash address in the memory plane.
The Flash memory plane is organized into several pages. Data to be written is stored in a load
buffer that corresponds to a Flash memory page. The load buffer is automatically flushed to
the Flash:
• before access to any page than the current one
• at the end of the number of words transmitted
The Write Page command (WP) is optimized for consecutive writes. Write handshaking can
be chained; an internal address buffer is automatically increased.
Flash Write Page and Lock command (WPL) is equivalent to the Flash Write Command.
However, the lock bit is automatically set at the end of the Flash write operation. As a lock
region is composed of several pages, the programmer writes to the first pages of the lock
region using Flash write commands and writes to the last page of the lock region using a Flash
write and lock command.
Flash Erase Page and Write command (EWP) is equivalent to the Flash Write Command.
However, before programming the load buffer, the page is erased.
Flash Erase Page and Write the Lock command (EWPL) combines EWP and WPL
commands.
Table 20-19. Read Command
Read/Write DR Data
Write (Number of Words to Read) << 16 | READ
Write Address
Read Memory [address]
Read Memory [address+4]
... ...
Read Memory [address+(Number of Words to Read - 1)* 4]
Table 20-20. Write Command
Read/Write DR Data
Write (Number of Words to Write) << 16 | (WP or WPL or EWP or EWPL)
Write Address
Write Memory [address]
Write Memory [address+4]
Write Memory [address+8]
Write Memory [address+(Number of Words to Write - 1)* 4]