![](http://datasheet.mmic.net.cn/90000/MC80C32E-12-883-D_datasheet_2371307/MC80C32E-12-883-D_294.png)
294
8272E–AVR–04/2013
ATmega164A/PA/324A/PA/644A/PA/1284/P
26.8.16
Atmel ATmega644A/ATmega644PA Boot Loader parameters
Note:
Note:
Note:
1. Z0: should be zero for all SPM commands, byte select for the (E)LPM instruction.
Programming.
Table 26-13. Boot size configuration
BOOTSZ1
BOOTSZ0
Boot size
Pages
Application
flash section
Boot loader
flash section
End
application
section
Boot reset
address
(start boot
loader section)
1
512 words
4
0x0000 - 0x7DFF
0x7E00 - 0x7FFF
0x7DFF
0x7E00
1
0
1024 words
8
0x0000 - 0x7BFF
0x7C00 - 0x7FFF
0x7BFF
0x7C00
0
1
2048 words
16
0x0000 - 0x77FF
0x7800 - 0x7FFF
0x77FF
0x7800
0
4096 words
32
0x0000 - 0x6FFF
0x7000 - 0x7FFF
0x6FFF
0x7000
Table 26-14. Read-While-Write limit
Section
Pages
Address
Read-While-Write section (RWW)
224
0x0000 - 0x6FFF
No Read-While-Write section (NRWW)
32
0x7000 - 0x7FFF
Variable
Corresponding
Z-value
PCMSB
14
Most significant bit in the Program Counter. (The Program Counter is 14 bits
PC[14:0])
PAGEMSB
7
Most significant bit which is used to address the words within one page (128
words in a page requires seven bits PC [6:0]).
ZPCMSB
Z15
Bit in Z-pointer that is mapped to PCMSB. Because Z0 is not used, the
ZPCMSB equals PCMSB + 1.
ZPAGEMSB
Z8
Bit in Z-pointer that is mapped to PCMSB. Because Z0 is not used, the
ZPAGEMSB equals PAGEMSB + 1.
PCPAGE
PC[14:7]
Z15:Z7
Program Counter page address: Page select, for Page Erase and Page Write
PCWORD
PC[6:0]
Z7:Z1
Program Counter word address: Word select, for filling temporary buffer (must
be zero during Page Write operation)