Datasheet

335
ATmega640/1280/1281/2560/2561
2549K–AVR–01/07
ATmega640 Boot Loader
Parameters
In Table 140 through Table 142, the parameters used in the description of the Self-Pro-
gramming are given.
Note: 1. The different BOOTSZ Fuse configurations are shown in Figure 136.
Note: 1. For details about these two section, see “NRWW – No Read-While-Write Section” on
page 324 and “RWW – Read-While-Write Section” on page 324.
Table 140. Boot Size Configuration, ATmega640
(1)
BOOTSZ1 BOOTSZ0 Boot Size Pages Appli-cation Flash Section Boot Loader Flash Section End Application Section Boot Reset Address (Start Boot Loader Section)
11
512
words
4
0x0000 -
0x7DFF
0x7E00 -
0x7FFF
0x7DFF 0x7E00
10
1024
words
8
0x0000 -
0x7BFF
0x7C00 -
0x7FFF
0x7BFF 0x7C00
01
2048
words
16
0x0000 -
0x77FF
0x7800 -
0x7FFF
0x77FF 0x7800
00
4096
words
32
0x0000 -
0x6FFF
0x7000 -
0x7FFF
0x6FFF 0x7000
Table 141. Read-While-Write Limit, ATmega640
Section
(1)
Pages Address
Read-While-Write section (RWW) 224 0x0000 - 0x6FFF
No Read-While-Write section (NRWW) 32 0x7000 - 0x7FFF
Table 142. Explanation of different variables used in Figure 137 and the mapping to the
Z-pointer, ATmega640
Variable
Corresponding
Z-value
(2)
Description
(1)
PCMSB 14 Most significant bit in the Program
Counter. (The Program Counter is 15 bits
PC[14:0])