Table 24-11. Read-while-write Limit
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 Section 24.3.2 “NRWW – No Read-while-write Section” on page 242 and Section
24.3.1 “RWW – Read-while-write Section” on page 242.
Table 24-12. Explanation of Different Variables used in Figure 24-3 and the Mapping to the Z-pointer
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
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.
ZPAGEMSB
PCPAGE
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:Z13: always ignored
Z0: should be zero for all SPM commands, byte select for the LPM instruction.
See Section 24.6 “Addressing the Flash during Self-Programming” on page 246 for details about the use of
Z-pointer during self-programming.
24.7.16 ATmega16/32/64/M1/C1 - 64K - Flash Boot Loader Parameters
In Table 24-13 through Table 24-15 on page 254, the parameters used in the description of the self programming are given.
Table 24-13. Boot Size Configuration, ATmega16/32/64/M1/C1 (64K Product)
Boot
Loader
Flash
Boot Reset
Address (Start
Boot Loader
Section)
Application
Flash
Section
End
Application
Section
Boot
BOOTSZ1
BOOTSZ0
Size(2)
Pages
Section
512
words
0x0000 -
0x7DFF
0x7E00 -
0x7FFF
1
1
4
0x7DFF
0x7BFF
0x77FF
0x6FFF
0x7E00
0x7C00
0x7800
0x7000
1024
words
0x0000 -
0x7BFF
0x7C00 -
0x7FFF
1
0
0
0
1
0
8
2048
words
0x7800 -
0x7FFF
16
32
0x0000 - 0x77FF
4096
words
0x0000 -
0x6FFF
0x7000 -
0x7FFF
Note:
1. The different BOOTSZ Fuse configurations are shown in Figure 24-2 on page 243.
2. 1 word equals 2 bytes.
ATmega16/32/64/M1/C1 [DATASHEET]
253
7647O–AVR–01/15
MICROCHIP [ MICROCHIP ]
