ATMEga64L ATMEL Corporation, ATMEga64L Datasheet - Page 289

• Manufacturer Part Number: ATMEga64L
• Description: 8-bit AVR Microcontroller with 64K Bytes In-System Programmable Flash
• Manufacturer: ATMEL Corporation

ATmega64 Boot Loader
Parameters
2490G–AVR–03/04
In Table 113 through Table 115, the parameters used in the description of the Self-pro-
gramming are given.
Table 113. Boot Size Configuration
Note:
Table 114. Read-While-Write Limit
Note:
Table 115. Explanation of Different Variables Used in Figure 137 and the Mapping to
the Z-pointer
Notes:
Section
Read-While-Write (RWW)
No Read-While-Write (NRWW)
PCMSB
PAGEMSB
ZPCMSB
ZPAGEMSB
PCPAGE
PCWORD
BOOTSZ
Variable
1
1
1
0
0
1. The different BOOTSZ Fuse configurations are shown in Figure 136
1. For details about these two section, see “NRWW – No Read-While-Write Section” on
1. Z0: should be zero for all SPM commands, byte select for the LPM instruction.
2. See “Addressing the Flash During Self-programming” on page 283 for details about
page 278 and “RWW – Read-While-Write Section” on page 278
the use of Z-pointer during Self-programming.
BOOTSZ
(1)(2)
PC[14:7]
PC[6:0]
0
1
0
1
0
14
6
Boot
Size
512
words
1024
words
2048
words
4096
words
Corresponding
Z-value
Z15:Z8
Z7:Z1
Z15
Z7
Pages
16
32
4
8
(1)
(1)
Appli-
cation
Flash
Section
0x0000 -
0x7DFF
0x0000 -
0x7BFF
0x0000 -
0x77FF
0x0000 -
0x6FFF
Description
Most significant bit in the Program Counter.
(The Program Counter is 15 bits PC[14:0]).
Most significant bit which is used to address the
words within one page (128 words in a page
requires seven bits PC [6:0]).
Bit in Z-register that is mapped to PCMSB.
Because Z0 is not used, the ZPCMSB equals
PCMSB + 1.
Bit in Z-register that is mapped to PAGEMSB.
Because Z0 is not used, the ZPAGEMSB
equals PAGEMSB + 1.
Program Counter page address: Page select,
for Page Erase and Page Write
Program Counter word address: Word select,
for filling temporary buffer (must be zero during
Page Write operation)
Boot
Loader
Flash
Section
0x7E00 -
0x7FFF
0x7C00 -
0x7FFF
0x7800 -
0x7FFF
0x7000 -
0x7FFF
Pages
224
32
ATmega64(L)
End
Applic-
ation
Section
0x7DFF
0x7BFF
0x77FF
0x6FFF
Address
0x0000 - 0x6FFF
0x7000 - 0x7FFF
Boot Reset
Address
(Start Boot
Loader
Section)
0x7E00
0x7C00
0x7800
0x7000
289