Rainbow Electronics ATmega8HVD - Manual (Page 126)

126
8052B–AVR–09/08
ATmega4HVD/8HVD
Table 23-3. Explanation of different variables used in Figure 23-1 and the mapping to the Z-
pointer for ATmega4HVD
Variable
Corresponding
Z-value Description
PCMSB 10
Most significant bit in the Program Counter. (The
Program Counter is 11 bits PC[10:0])
PAGEMSB 4
Most significant bit which is used to address the
words within one page (32 words in a page requires
six bits PC[4:0]).
ZPCMSB Z11
Bit in Z-register that is mapped to PCMSB.
Because Z0 is not used, the ZPCMSB equals
PCMSB + 1.
ZPAGEMSB Z5
Bit in Z-register that is mapped to PAGEMSB.
Because Z0 is not used, the ZPAGEMSB equals
PAGEMSB + 1.
PCPAGE PC[10:5] Z11:Z6
Program Counter page address: Page select, for
Page Erase and Page Write
PCWORD PC[4:0] Z5:Z1
Program Counter word address: Word select, for
filling temporary buffer (must be zero during Page
Write operation)
Table 23-4. Explanation of different variables used in Figure 23-1 and the mapping to the Z-
pointer for ATmega8HVD
Variable
Corresponding
Z-value Description
PCMSB 11
Most significant bit in the Program Counter. (The
Program Counter is 12 bits PC[11:0])
PAGEMSB 4
Most significant bit which is used to address the
words within one page (32 words in a page requires
six bits PC[4:0]).
ZPCMSB Z12
Bit in Z-register that is mapped to PCMSB.
Because Z0 is not used, the ZPCMSB equals
PCMSB + 1.
ZPAGEMSB Z5
Bit in Z-register that is mapped to PAGEMSB.
Because Z0 is not used, the ZPAGEMSB equals
PAGEMSB + 1.
PCPAGE PC[11:5] Z12:Z6
Program Counter page address: Page select, for
Page Erase and Page Write
PCWORD PC[4:0] Z5:Z1
Program Counter word address: Word select, for
filling temporary buffer (must be zero during Page
Write operation)