113
2588F–AVR–06/2013
ATtiny261/461/861
Table 12-10 shows the COM1A1:0 bit functionality when the PWM1A, WGM10 and WGM11 bits
are set to Phase and Frequency Correct PWM Mode.
Table 12-11 shows the COM1A1:0 bit functionality when the PWM1A, WGM10 and WGM11 bits
are set to single-slope PWM6 Mode. In the PWM6 Mode the same Waveform Output (OCW1A)
is used for generating all waveforms and the Output Compare values OC1A and OC1A are con-
nected on thw all OC1x and OC1x pins as described below.
Table 12-12 shows the COM1A1:0 bit functionality when the PWM1A, WGM10 and WGM11 bits
are set to dual-slope PWM6 Mode.I
Bits COM1A1 and COM1A0 are shadowed in TCCR1C. Writing to bits COM1A1 and COM1A0
will also change bits COM1A1S and COM1A0S in TCCR1C. Similary, changes written to bits
Table 12-10. Compare Output Mode, Phase and Frequency Correct PWM Mode
COM1A1:0
OCW1A Behaviour
OC1A Pin
00
Normal port operation.
Disconnected
01
Cleared on Compare Match when up-counting.
Set on Compare Match when down-counting.
Connected
10
Cleared on Compare Match when up-counting.
Set on Compare Match when down-counting.
Connected
Disconnected
11
Set on Compare Match when up-counting.
Cleared on Compare Match when down-counting.
Connected
Disconnected
Table 12-11. Compare Output Mode, Single-Slope PWM6 Mode
COM1A1:0
OCW1A Behaviour
OC1x Pin
00
Normal port operation.
Disconnected
01
Cleared on Compare Match.
Set when TCNT1 = 0x000.
OC1A
10
Cleared on Compare Match.
Set when TCNT1 = 0x000.
OC1A
11
Set on Compare Match.
Cleared when TCNT1 = 0x000.
OC1A
Table 12-12. Compare Output Mode, Dual-Slope PWM6 Mode
COM1A1:0
OCW1A Behaviour
OC1x Pin
00
Normal port operation.
Disconnected
01
Cleared on Compare Match when up-counting.
Set on Compare Match when down-counting.
OC1A
10
Cleared on Compare Match when up-counting.
Set on Compare Match when down-counting.
OC1A
11
Set on Compare Match when up-counting.
Cleared on Compare Match when down-counting.
OC1A