Bits 6 and 5—Counter Clear 1/0 (CCLR1, CCLR0): These bits select how TCNT is cleared.
Bit 6
Bit 5
CCLR1
CCLR0
Description
0
0
TCNT is not cleared
(Initial value)
1
TCNT is cleared by GRA compare match or input capture
*
1
1
0
TCNT is cleared by GRB compare match or input capture
*
1
1
Synchronous clear: TCNT is cleared in synchronization with other
synchronized timers
*
2
Notes: 1. TCNT is cleared by compare match when the general register functions as an output
compare register, and by input capture when the general register functions as an input
capture register.
2. Selected in TSNC.
Bits 4 and 3—Clock Edge 1/0 (CKEG1, CKEG0): These bits select external clock input edges
when an external clock source is used.
Bit 4
Bit 3
CKEG1
CKEG0
Description
0
0
Count rising edges
(Initial value)
1
Count falling edges
1
—
Count both edges
When channel 2 is set to phase counting mode, bits CKEG1 and CKEG0 in TCR2 are ignored.
Phase counting takes precedence.
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