Datasheet

ATtiny2313/V

2543H–AVR–02/05

Timer/Counter Control

• Bit 7 – FOC0A: Force Output Compare A

The FOC0A bit is only active when the WGM bits specify a non-PWM mode.

However, for ensuring compatibility with future devices, this bit must be set to zero when

TCCR0B is written when operating in PWM mode. When writing a logical one to the

FOC0A bit, an immediate Compare Match is forced on the Waveform Generation unit.

The OC0A output is changed according to its COM0A1:0 bits setting. Note that the

FOC0A bit is implemented as a strobe. Therefore it is the value present in the

COM0A1:0 bits that determines the effect of the forced compare.

A FOC0A strobe will not generate any interrupt, nor will it clear the timer in CTC mode

using OCR0A as TOP.

The FOC0A bit is always read as zero.

• Bit 6 – FOC0B: Force Output Compare B

The FOC0B bit is only active when the WGM bits specify a non-PWM mode.

However, for ensuring compatibility with future devices, this bit must be set to zero when

TCCR0B is written when operating in PWM mode. When writing a logical one to the

FOC0B bit, an immediate Compare Match is forced on the Waveform Generation unit.

The OC0B output is changed according to its COM0B1:0 bits setting. Note that the

FOC0B bit is implemented as a strobe. Therefore it is the value present in the

COM0B1:0 bits that determines the effect of the forced compare.

A FOC0B strobe will not generate any interrupt, nor will it clear the timer in CTC mode

using OCR0B as TOP.

The FOC0B bit is always read as zero.

• Bits 5:4 – Res: Reserved Bits

These bits are reserved bits in the ATtiny2313 and will always read as zero.

• Bit 3 – WGM02: Waveform Generation Mode

See the description in the “Timer/Counter Control Register A – TCCR0A” on page 73.

• Bits 2:0 – CS02:0: Clock Select

The three Clock Select bits select the clock source to be used by the Timer/Counter.

See Table 41 on page 77.

Bit 7 6 5 4 3 2 1 0

FOC0A FOC0B – – WGM02 CS02 CS01 CS00 TCCR0B

Read/Write W W R R R/W R/W R/W R/W

Initial Value 0 0 0 0 0 0 0 0