Rainbow-electronics ATmega8HVD Manuel d'utilisateur télécharger pdf (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])

PAG EMSB 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