ATmega48PA/88PA/168PA/328P
26.8.16 ATmega328P Boot Loader Parameters
In Table 26-13 through Table 26-15, the parameters used in the description of the self programming are given.
Table 26-13. Boot Size Configuration, ATmega328P
Boot
Application
Flash
Section
Loader
Flash
Section
End
Application
Section
Boot
Size
Boot Reset Address (Start Boot
Loader Section)
BOOTSZ1
BOOTSZ0
Pages
1
1
0
0
1
0
1
0
256 words
512 words
4
8
0x0000 - 0x3EFF
0x0000 - 0x3DFF
0x0000 - 0x3BFF
0x0000 - 0x37FF
0x3F00 - 0x3FFF
0x3E00 - 0x3FFF
0x3C00 - 0x3FFF
0x3800 - 0x3FFF
0x3EFF
0x3DFF
0x3BFF
0x37FF
0x3F00
0x3E00
0x3C00
0x3800
1024 words
2048 words
Note:
16
32
The different BOOTSZ Fuse configurations are shown in Figure 26-2 on page 280.
Table 26-14. Read-While-Write Limit, ATmega328P
Section
Pages
224
Address
Read-While-Write section (RWW)
No Read-While-Write section (NRWW)
0x0000 - 0x37FF
0x3800 - 0x3FFF
32
For details about these two section, see ”NRWW – No Read-While-Write Section” on page 278 and ”RWW – Read-While-
Write Section” on page 278.
Table 26-15. Explanation of Different Variables used in Figure 26-3 and the Mapping to the Z-pointer, ATmega328P
Corresponding
Variable
Z-value(1)
Description
Most significant bit in the Program Counter. (The Program Counter
is 14 bits PC[13:0])
PCMSB
13
5
Most significant bit which is used to address the words within
one page (64 words in a page requires 6 bits PC [5:0])
PAGEMSB
ZPCMSB
ZPAGEMSB
PCPAGE
Bit in Z-register that is mapped to PCMSB. Because Z0 is not used,
the ZPCMSB equals PCMSB + 1.
Z14
Z6
Bit in Z-register that is mapped to PAGEMSB. Because Z0 is not
used, the ZPAGEMSB equals PAGEMSB + 1.
Program counter page address: Page select, for page erase and
page write
PC[13:6]
PC[5:0]
Z14:Z7
Z6:Z1
Program counter word address: Word select, for filling temporary
buffer (must be zero during page write operation)
PCWORD
Note:
1. Z15: always ignored
Z0: should be zero for all SPM commands, byte select for the LPM instruction.
See ”Addressing the Flash During Self-Programming” on page 282 for details about the use of Z-pointer during Self-
Programming.
291
8161D–AVR–10/09
ATMEL [ ATMEL ]
