Rainbow Electronics ATmega64C1 User Manual
Page 288
288
7647A–AVR–02/08
ATmega32/64/M1/C1
23.7.15
ATmega32/64/M1/C1 - 64K - Flash Boot Loader Parameters
In
, the parameters used in the description of the self program-
ming are given.
Note:
1. The different BOOTSZ Fuse configurations are shown in
2. 1 word equals 2 bytes.
For details about these two section, see
“NRWW – No Read-While-Write Section” on page 274
and
“RWW – Read-While-Write Section” on page 274
Note:
Z15:Z13: always ignored
Z0: should be zero for all SPM commands, byte select for the LPM instruction.
Table 23-10. Boot Size Configuration, ATmega32/64/M1/C1 (64K product)
BOOTSZ1
BOOTSZ0
Boot
Size
(2)
Pages
Application
Flash
Section
Boot
Loader
Flash
Section
End
Application
Section
Boot Reset
Address
(Start Boot
Loader
Section)
1
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
0
4096
words
32
0x0000 -
0x6FFF
0x7000 -
0x7FFF
0x6FFF
0x7000
Table 23-11. Read-While-Write Limit
Section
Pages
Address
Read-While-Write section (RWW)
224
0x0000 - 0x37FF
No Read-While-Write section (NRWW)
32
0x3800 - 0x3FFF
Table 23-12. Explanation of Different Variables used in
and the Mapping to the Z-
pointer
Variable
Corresponding
Z-value
Description
PCMSB
14
Most significant bit in the Program Counter. (The Program
Counter is 15 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-register that is mapped to PCMSB. Because Z0 is
not used, the ZPCMSB equals PCMSB + 1.
ZPAGEMSB
Z8
Bit in Z-register that is mapped to PAGEMSB. 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)