
Example of Phase Counting Mode: Figure 10-44 shows an example of operations in phase
counting mode. Table 10-9 lists the up-counting and down-counting conditions for TCNT2.
In phase counting mode both the rising and falling edges of TCLKA and TCLKB are counted.
The phase difference between TCLKA and TCLKB must be at least 1.5 states, the phase overlap
must also be at least 1.5 states, and the pulse width must be at least 2.5 states. See figure 10-45.
Figure 10-44 Operation in Phase Counting Mode (Example)
Table 10-9 Up/Down Counting Conditions
Counting Direction
Up-Counting
Down-Counting
TCLKB
High
Low
High
Low
TCLKA
Low
High
Low
High
Figure 10-45 Phase Difference, Overlap, and Pulse Width in Phase Counting Mode
TCNT2 value
Counting up
Counting down
Time
TCLKB
TCLKA
TCLKA
TCLKB
Phase
difference
Phase
difference
Pulse width
Pulse width
Overlap
Overlap
Phase difference and overlap:
Pulse width:
at least 1.5 states
at least 2.5 states
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