Datasheet
290
ATmega169A/PA/329A/PA/649A/P/3290A/PA/6490A/P [DATASHEET]
8284E–AVR–02/2013
Notes: 1. Z15:Z14: 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 283 for details about the use of Z-pointer during
Self-Programming.
27.8.13.2 Atmel ATmega329A/329PA/3290A/3290PA/649A/649P/6490A/6490P
In Table 27-9 through Table 27-11, the parameters used in the description of the Self-Programming are given.
Note: 1. The different BOOTSZ Fuse configurations are shown in Figure 27-2.
Note: 1. For details about these two section, see ”NRWW – No Read-While-Write Section” on page 279 and ”RWW – Read-While-
Write Section” on page 279.
Table 27-8. Explanation of different variables used in Figure 27-3 on page 284 and the mapping to the Z-pointer
(Atmel ATmega169A/169PA)
(1)
.
Variable
Corresponding
Z-value Description
PCMSB 12
Most significant bit in the Program Counter.
(The Program Counter is 13 bits PC[12:0])
PAGEMSB 5
Most significant bit which is used to address the words
within one page (64 words in a page requires six bits PC
[5:0]).
ZPCMSB Z13
Bit in Z-register that is mapped to PCMSB. Because Z0
is not used, the ZPCMSB equals PCMSB + 1.
ZPAGEMSB Z6
Bit in Z-register that is mapped to PAGEMSB. Because
Z0 is not used, the ZPAGEMSB equals PAGEMSB + 1.
PCPAGE PC[12:6] Z13:Z7
Program Counter page address: Page select, for Page
Erase and Page Write
PCWORD PC[5:0] Z6:Z1
Program Counter word address: Word select, for filling
temporary buffer (must be zero during Page Write
operation)
Table 27-9. Boot Size configuration (ATmega329A/329PA/3290A/3290PA/649A/649P/6490A/6490P)
(1)
.
BOOTSZ1 BOOTSZ0 Boot Size Pages
Application
flash section
Boot Loader
flash section
End
application
section
Boot Reset
address
(Start
Boot Loader
section)
1 1 256 words 4 0x0000-0x3EFF 0x3F00-0x3FFF 0x3EFF 0x3F00
1 0 512 words 8 0x0000-0x3DFF 0x3E00-0x3FFF 0x3DFF 0x3E00
0 1 1024 words 16 0x0000-0x3BFF 0x3C00-0x3FFF 0x3BFF 0x3C00
0 0 2048 words 32 0x0000-0x37FF 0x3800-0x3FFF 0x37FF 0x3800
Table 27-10. Read-While-Write Limit (ATmega329A/329PA/3290A/3290PA/649A/649P/6490A/6490P)
(1)
.
Section Pages Address
Read-While-Write section (RWW) 224 0x0000 - 0x37FF
No Read-While-Write section (NRWW) 32 0x3800 - 0x3FFF