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254
ATmega165A/PA/325A/PA/3250A/PA/645A/P/6450A/P [DATASHEET]
8285E–AVR–02/2013
Note:
Note:
1. Z0: should be zero for all SPM commands, byte select for the LPM instruction.
Programming.
Table 26-10. Read-While-Write limit
(1) (Atmel ATmega325A/325PA/3250A/3250PA/625A/645P/6450A/6450P).
Section
Pages
Address
Read-While-Write section (RWW)
224/224
0x0000 - x37FF/ 0x0000 - 0x6FFF
No Read-While-Write section (NRWW)
32/32
0x3800 - 0x3FFF/ 0x7000-0x7FFF
(Atmel ATmega325A/325PA/3250A/3250PA/625A/645P/6450A/6450P).
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)