XMEGAD datasheet(19/309 Pages) ATMEL

19 / 309 page

8210B–AVR–04/10

XMEGA D

All AVR instructions are 16 or 32 bits wide, and each Flash location is 16 bits wide. The Flash

memory in XMEGA is organized in two main sections, the Application Section and the Boot

Loader section, as shown in Figure 4-1 on page 19. The sizes of the different sections are fixed,

but device dependent. These two sections have separate lock bits and can have different level

of protection. The Store Program Memory (SPM) instruction used to write to the Flash from the

application software, will only operate when executed from the Boot Loader Section.

The Application Section contains an Application Table Section with separate lock settings. This

can be used for safe storage of Non-volatile data in the Program Memory.

Figure 4-1.

Flash Memory sections

4.3.1

Application Section

The Application section is the section of the Flash that is used for storing the executable applica-

tion code. The protection level for the Application section can be selected by the Boot Lock Bits

for this section. The Application section can not store any Boot Loader code since the SPM

instruction cannot be executed from the Application section.

4.3.2

Application Table section

The Application Table section is a part of the Application Section of the Flash that can be used

for storing data. The size is identical to the Boot Loader Section. The protection level for the

Application Table section can be selected by the Boot Lock Bits for this section. The possibilities

Application Flash

Section

0x000000

End RWW, End Application

Start NRWW, Start Boot Loader

Flashend

Application Table

Flash Section

Boot Loader Flash

Section

XMEGAD 데이터시트(PDF) 19 Page - ATMEL Corporation