ATmega48PA/88PA/168PA/328P
26.8.14 ATmega88PA Boot Loader Parameters
In Table 26-7 through Table 26-9, the parameters used in the description of the self programming are given.
Table 26-7. Boot Size Configuration, ATmega88PA
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
128 words
256 words
512 words
4
8
0x000 - 0xF7F
0x000 - 0xEFF
0x000 - 0xDFF
0x000 - 0xBFF
0xF80 - 0xFFF
0xF00 - 0xFFF
0xE00 - 0xFFF
0xC00 - 0xFFF
0xF7F
0xEFF
0xDFF
0xBFF
0xF80
0xF00
0xE00
0xC00
16
32
1024 words
Note:
The different BOOTSZ Fuse configurations are shown in Figure 26-2 on page 280.
Table 26-8. Read-While-Write Limit, ATmega88PA
Section
Pages
96
Address
Read-While-Write section (RWW)
No Read-While-Write section (NRWW)
0x000 - 0xBFF
0xC00 - 0xFFF
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 26-9. Explanation of Different Variables used in Figure 26-3 and the Mapping to the Z-pointer, ATmega88PA
Corresponding
Variable
Z-value(1)
Description
Most significant bit in the Program Counter. (The Program Counter is
12 bits PC[11:0])
PCMSB
11
4
Most significant bit which is used to address the words within one
page (32 words in a page requires 5 bits PC [4:0]).
PAGEMSB
ZPCMSB
ZPAGEMSB
PCPAGE
Bit in Z-register that is mapped to PCMSB. Because Z0 is not used,
the ZPCMSB equals PCMSB + 1.
Z12
Z5
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[11:5]
PC[4:0]
Z12:Z6
Z5:Z1
Program counter word address: Word select, for filling temporary
buffer (must be zero during page write operation)
PCWORD
Note:
1. Z15:Z13: 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.
289
8161D–AVR–10/09
ATMEL [ ATMEL ]
