Rainbow Electronics ATmega3290P_V - Manual (Page 280)

280
ATmega329/3290/649/6490
2552H–AVR–11/06
ATmega329/3290/649/6490
Boot Loader Parameters In Table 120 through Table 122, the parameters used in the description of the Self-Pro-
gramming are given.
Note: 1. The different BOOTSZ Fuse configurations are shown in Figure 118
Note: 1. For details about these two section, see “NRWW – No Read-While-Write Section” on page 269 and “RWW – Read-While-
Write Section” on page 269.
Notes: 1. Z0: should be zero for all SPM commands, byte select for the LPM instruction. See “Addressing the Flash During Self-Pro-
gramming” on page 273 for details about the use of Z-pointer during Self-Programming.
Table 120. Boot Size Configuration (1)
BOOTSZ1 BOOTSZ0 Boot Size Pages
Application
Flash Section Boot Loader
Flash Section
End
Application
Section
Boot Reset
Address
(Start
Boot Loader
Section)
1 1 256/512 words 4 0x0000-0x3EFF/
0x0000 -0x7DFF
0x3F00-0x3FFF/
0x7E00-0x7FFF
0x3EFF/
0x7DFF 0x3F00/
0x7E00
1 0 512/1024 words 8 0x0000-0x3DFF/
0x0000-0x7BFF/
0x3E00-0x3FFF/
0x7C00-0x7FFF
0x3DFF/
0x7BFF 0x3E00/
0x7C00
0 1 1024/2048 words 16 0x0000-0x3BFF/
0x0000-0x77FF
0x3C00-0x3FFF/
0x7800-0x7FFF
0x3BFF/
0x77FF 0x3C00
0x7800
0 0 2048/4096 words 32 0x0000-0x37FF/
0x0000 -0x6FFF
0x3800-0x3FFF/
0x7000-0x7FFF
0x37FF/
0x6FFF 0x3800/
0x7000
Table 121. Read-While-Write Limit (1)
Section Pages Address
Read-While-Write section (RWW) 224/224 0x0000 - 0x37FF/ 0x0000 - 0x6FFF
No Read-While-Write section (NRWW) 32/32 0x3800 - 0x3FFF/ 0x7000-0x7FFF
Table 122. Explanation of different variables used in Figure 119 and the mapping to the Z-pointer (1)
Variable
Corresponding
Z-value Description
PCMSB 13/14
Most significant bit in the Program Counter. (Program Counter is 14/15
bits PC[13/14:0])
PAGEMSB 5/6
Most significant bit which is used to address the words within one page
(64/128 words in a page requires six/seven bits PC [5/6:0]).
ZPCMSB Z14/15
Bit in Z-register that is mapped to PCMSB. Because Z0 is not used, the
ZPCMSB equals PCMSB + 1.
ZPAGEMSB Z6/7
Bit in Z-register that is mapped to PCMSB. Because Z0 is not used, the
ZPAGEMSB equals PAGEMSB + 1.
PCPAGE PC[13/14:6/7] Z14/15:Z7/8
Program Counter page address: Page select, for Page Erase and Page
Write
PCWORD PC[5/6:0] Z6/7:Z1
Program Counter word address: Word select, for filling temporary buffer
(must be zero during Page Write operation)