335
7679H–CAN–08/08
AT90CAN32/64/128
Notes:
1. See
“Addressing the Flash During Self-Programming” on page 327
for details about the use of
Z-pointer during self-programming.
2. Z0: should be zero for all SPM commands, byte select for the (E)LPM instruction.
3. The Z-register is only 16 bits wide. Bit 16 is located in RAMPZ register in I/O map.
Table 24-8.
Explanation of Different Variables Used in
and the Mapping to the Z-Pointer
D
evice
Va
ri
a
b
le
Nam
e
Va
ri
a
b
le
Va
lu
e
Corresponding
Z-value
Description
A
T
9
0
CAN3
2
PCMSB
13
Most significant bit in the program counter. (The program counter is 14 bits PC[13:0])
PAGEMSB
6
Most significant bit which is used to address the words within one page (128 words in a page
requires 7 bits PC [6:0]).
ZPCMSB
Z14
Bit in Z-register that is mapped to PCMSB. Because Z0 is not used, the ZPCMSB equals
PCMSB + 1.
ZPAGEMSB
Z7
Bit in Z-register that is mapped to PAGEMSB. Because Z0 is not used, the ZPAGEMSB
equals P 1.
PCPAGE
PC[13:7]
Z14:Z7
Program counter page address: Page select, for Page Erase and Page Write.
PCWORD
PC[6:0]
Z7:Z1
Program counter word address: Word select, for filling temporary buffer (must be zero during
PAGE WRITE operation).
A
T
90CAN
64
PCMSB
14
Most significant bit in the program counter. (The program counter is 15 bits PC[14:0])
PAGEMSB
6
Most significant bit which is used to address the words within one page (128 words in a page
requires 7 bits PC [6:0]).
ZPCMSB
Z15
Bit in Z-register that is mapped to PCMSB. Because Z0 is not used, the ZPCMSB equals
PCMSB + 1.
ZPAGEMSB
Z7
Bit in Z-register that is mapped to PAGEMSB. Because Z0 is not used, the ZPAGEMSB
equals P 1.
PCPAGE
PC[14:7]
Z15:Z7
Program counter page address: Page select, for Page Erase and Page Write.
PCWORD
PC[6:0]
Z7:Z1
Program counter word address: Word select, for filling temporary buffer (must be zero during
PAGE WRITE operation).
A
T
90
CAN12
8
PCMSB
15
Most significant bit in the program counter. (The program counter is 16 bits PC[15:0])
PAGEMSB
6
Most significant bit which is used to address the words within one page (128 words in a page
requires 7 bits PC [6:0]).
ZPCMSB
Z16
Bit in Z-register that is mapped to PCMSB. Because Z0 is not used, the ZPCMSB equals
PCMSB + 1.
ZPAGEMSB
Z7
Bit in Z-register that is mapped to PAGEMSB. Because Z0 is not used, the ZPAGEMSB
equals P 1.
PCPAGE
PC[15:7]
Z16
:Z7
Program counter page address: Page select, for Page Erase and Page Write.
PCWORD
PC[6:0]
Z7:Z1
Program counter word address: Word select, for filling temporary buffer (must be zero during
PAGE WRITE operation).