290
2552K–AVR–04/11
ATmega329/3290/649/6490
26.7.13
ATmega329/3290/649/6490 Boot Loader Parameters
ming are given.
Notes:
1. The different BOOTSZ Fuse configurations are shown in
Figure 26-2Notes:
Notes:
Table 26-6.
Boot Size Configuration
(1)BOOTSZ1
BOOTSZ0
Boot Size
Pages
Application
Flash Section
Boot Loader
Flash Section
End
Application
Section
Boot Reset
Address
(Start
Boot Loader
Section)
1
256/512 words
4
0x0000-0x3EFF/
0x0000 -0x7DFF
0x3F00-0x3FFF/
0x7E00-0x7FFF
0x3EFF/
0x7DFF
0x3F00/
0x7E00
1
0
512/1024 words
8
0x0000-0x3DFF/
0x0000-0x7BFF/
0x3E00-0x3FFF/
0x7C00-0x7FFF
0x3DFF/
0x7BFF
0x3E00/
0x7C00
0
1
1024/2048 words
16
0x0000-0x3BFF/
0x0000-0x77FF
0x3C00-0x3FFF/
0x7800-0x7FFF
0x3BFF/
0x77FF
0x3C00
0x7800
0
2048/4096 words
32
0x0000-0x37FF/
0x0000 -0x6FFF
0x3800-0x3FFF/
0x7000-0x7FFF
0x37FF/
0x6FFF
0x3800/
0x7000
Table 26-7.
Section
Pages
Address
Read-While-Write section (RWW)
224/224
0x0000 - 0x37FF/ 0x0000 - 0x6FFF
No Read-While-Write section (NRWW)
32/32
0x3800 - 0x3FFF/ 0x7000-0x7FFF
Table 26-8.
Explanation of different variables used in
Figure 26-3 and the mapping to the Z-pointer
(1)Variable
Corresponding
Z-value
Description
PCMSB
13/14
Most significant bit in the Program Counter. (Program Counter is 14/15
bits PC[13/14:0])
PAGEMSB
5/6
Most significant bit which is used to address the words within one page
(64/128 words in a page requires six/seven bits PC [5/6:0]).
ZPCMSB
Z14/15
Bit in Z-register that is mapped to PCMSB. Because Z0 is not used, the
ZPCMSB equals PCMSB + 1.
ZPAGEMSB
Z6/7
Bit in Z-register that is mapped to PCMSB. Because Z0 is not used, the
ZPAGEMSB equals PAGEMSB + 1.
PCPAGE
PC[13/14:6/7]
Z14/15:Z7/8
Program Counter page address: Page select, for Page Erase and Page
Write
PCWORD
PC[5/6:0]
Z6/7:Z1
Program Counter word address: Word select, for filling temporary buffer
(must be zero during Page Write operation)