Rainbow Electronics ATtiny861_V User Manual

Page 114

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114

2588B–AVR–11/06

ATtiny261/461/861

Table 16-8

shows the COM1A1:0 bit functionality when the PWM1A, WGM10 and WGM11 bits

are set to Phase and Frequency Correct PWM Mode.

Table 16-9

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 16-10

shows the COM1A1:0 bit functionality when the PWM1A, WGM10 and WGM11 bits

are set to dual-slope PWM6 Mode.I

• Bits 5,4 - COM1B1, COM1B0: Comparator B Output Mode, Bits 1 and 0

These bits control the behaviour of the Waveform Output (OCW1B) and the connection of the
Output Compare pin (OC1B). If one or both of the COM1B1:0 bits are set, the OC1B output
overrides the normal port functionality of the I/O pin it is connected to. The complementary
OC1B output is connected only in PWM modes when the COM1B1:0 bits are set to “01”. Note

Table 16-8.

Compare Output Mode, Phase and Frequency Correct PWM Mode

COM1A1..0

OCW1A Behaviour

OC1A Pin

OC1A Pin

00

Normal port operation.

Disconnected

Disconnected

01

Cleared on Compare Match when up-counting.

Set on Compare Match when down-counting.

Connected

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 16-9.

Compare Output Mode, Single-Slope PWM6 Mode

COM1A1..0

OCW1A Behaviour

OC1x Pin

OC1x Pin

00

Normal port operation.

Disconnected

Disconnected

01

Cleared on Compare Match.

Set when TCNT1 = 0x000.

OC1A

OC1A

10

Cleared on Compare Match.

Set when TCNT1 = 0x000.

OC1A

OC1A

11

Set on Compare Match.

Cleared when TCNT1 = 0x000.

OC1A

OC1A

Table 16-10. Compare Output Mode, Dual-Slope PWM6 Mode

COM1A1..0

OCW1A Behaviour

OC1x Pin

OC1x Pin

00

Normal port operation.

Disconnected

Disconnected

01

Cleared on Compare Match when up-counting.

Set on Compare Match when down-counting.

OC1A

OC1A

10

Cleared on Compare Match when up-counting.

Set on Compare Match when down-counting.

OC1A

OC1A

11

Set on Compare Match when up-counting.

Cleared on Compare Match when down-counting.

OC1A

OC1A

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