ATXMEGA16E5_14 Datasheet, PDF (15/147 Pages) ATMEL Corporation – 8/16-bit Atmel AVR XMEGA Microcontrollers

8.11
I/O Memory Protection
Some features in the device are regarded as critical for safety in some applications. Due to this, it is possible to lock the
I/O register related to the clock system, the event system, and the waveform extensions. As long as the lock is enabled,
all related I/O registers are locked and they cannot be written from the application software. The lock registers
themselves are protected by the configuration change protection mechanism.
8.12
Flash and EEPROM Page Size
The flash program memory and EEPROM data memory are organized in pages. The pages are word accessible for the
flash and byte accessible for the EEPROM.
Table 8-2 shows the Flash Program Memory organization and Program Counter (PC) size. Flash write and erase
operations are performed on one page at a time, while reading the Flash is done one byte at a time. For Flash access the
Z-pointer (Z[m:n]) is used for addressing. The most significant bits in the address (FPAGE) give the page number and the
least significant address bits (FWORD) give the word in the page.
Table 8-2. Number of words and pages in the flash.
Devices
ATxmega32E5
ATxmega16E5
ATxmega8E5
PC size
bits
15
14
13
Flash size Page Size FWORD
bytes
words
32K+4K 64
16K+4K 64
8K+2K
64
Z[6:0]
Z[6:0]
Z[6:0]
FPAGE
Z[14:7]
Z[13:7]
Z[12:7]
Application
Size
No of
pages
32K
256
16K
128
8K
64
Boot
Size
No of
pages
4K
32
4K
32
2K
16
Table 8-3 shows EEPROM memory organization for the Atmel AVR XMEGA E5 devices. EEPROM write and erase
operations can be performed one page or one byte at a time, while reading the EEPROM is done one byte at a time. For
EEPROM access the NVM address register (ADDR[m:n]) is used for addressing. The most significant bits in the address
(E2PAGE) give the page number and the least significant address bits (E2BYTE) give the byte in the page.
Table 8-3. Number of words and pages in the EEPROM.
Devices
ATxmega32E5
ATxmega16E5
ATxmega8E5
EEPROM
Size
1K
512Bytes
512Bytes
Page Size
bytes
32
32
32
E2BYTE
ADDR[4:0]
ADDR[4:0]
ADDR[4:0]
E2PAGE
ADDR[10:5]
ADDR[10:5]
ADDR[10:5]
No of Pages
32
16
16
XMEGA E5 [DATASHEET] 15
Atmel-8153I–AVR-ATxmega8E5-ATxmega16E5-ATxmega32E5_Datasheet–08/2014