
146
8024A–AVR–04/08
ATmega8HVA/16HVA
26.2.6
Programming Time for Flash when Using SPM
The Fast RC Oscillator is used to time Flash accesses.
Table 26-2 shows the typical program-
ming time for Flash accesses from the CPU.
Note:
1. Minimum and maximum programming times is per individual operation.
Table 26-2.
SPM Programming Time, f
OSC = 8.0 MHz
Symbol
Min Programming Time
Max Programming Time
Flash write (Page Erase, Page Write, and
write Lock bits by SPM)
3.7 ms
4.5 ms
Table 26-3.
Explanation of different variables used in
Figure 26-1 and the mapping to the Z-
pointer, ATmega8HVA.
Variable
Corresponding
Z-value
Description
PCMSB
11
Most significant bit in the Program Counter. (The
Program Counter is 12 bits PC[11:0])
PAGEMSB
5
Most significant bit which is used to address the
words within one page (64 words in a page requires
six bits PC [5:0]).
ZPCMSB
Z12
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[11:6]
Z12: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)
Table 26-4.
Explanation of different variables used in
Figure 26-1 and the mapping to the Z-
pointer, ATmega16HVA.
Variable
Corresponding
Z-value
Description
PCMSB
12
Most significant bit in the Program Counter. (The
Program Counter is 13 bits PC[12:0])