Rainbow Electronics ATmega162V - Manual (Page 229)

229
ATmega162/V
2513E–AVR–09/03
Note: 1. Z15:Z14: 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 222 for details about
the use of Z-pointer during Self-programming.
Table 96. Explanation of Different Variables Used in Figure 95 and the Mapping to the
Z-pointer
(1)
Variable
Corresponding
Z-value Description
PCMSB
12 Most significant bit in the Program Counter.
(The Program Counter is 13 bits PC[12:0])
PAGEMSB
5 Most significant bit which is used to address
the words within one page (64 words in a page
requires 6 bits PC [5:0]).
ZPCMSB
Z13 Bit in Z-register that is mapped to PCMSB.
Because Z0 is not used, the ZPCMSB equals
PCMSB + 1.
ZPAGEMSB
Z6 Bit in Z-register that is mapped to PCMSB.
Because Z0 is not used, the ZPAGEMSB
equals PAGEMSB + 1.
PCPAGE
PC[12:6] Z13:Z7 Program Counter page address: Page select,
for Page Erase and Page Write
PCWORD
PC[5:0] Z6:Z1 Program Counter word address: Word select,
for filling temporary buffer (must be zero during
Page Write operation)