Atmel ATmega32M1 Manual page 295

7647H–AVR–03/12
For details about these two section, see
and "RWW – Read-While-Write Section" on page
Table 24-15. Explanation of Different Variables used in
Z-pointer
Variable
PCMSB 14
PAGEMSB 7
ZPCMSB
ZPAGEMSB
PCPAGE PC[14:7]
PCWORD PC[6:0]
Note: Z15:Z13: always ignored
Z0: should be zero for all SPM commands, byte select for the LPM instruction.
See "Addressing the Flash During Self-Programming" on page 285
Z-pointer during Self-Programming.
Atmel ATmega16/32/64/M1/C1
"NRWW – No Read-While-Write Section" on page 280
280.
Corresponding
(Note:)
Z-value 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
Z15
Z0 is not used, the ZPCMSB equals PCMSB + 1.
Bit in Z-register that is mapped to PAGEMSB.
Z8 Because Z0 is not used, the ZPAGEMSB equals
PAGEMSB + 1.
Program counter page address: Page select, for page
Z15:Z8
erase and page write
Program counter word address: Word select, for filling
Z7:Z1 temporary buffer (must be zero during page write
operation)
Figure 24-3 and the Mapping to the
for details about the use of
295