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Atmega162/v – Rainbow Electronics ATmega162V User Manual

Page 195

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195

ATmega162/V

2513E–AVR–09/03

the ACIE bit is set and the I-bit in SREG is set. ACI is cleared by hardware when execut-
ing the corresponding interrupt handling vector. Alternatively, ACI is cleared by writing a
logic one to the flag.

• Bit 3 – ACIE: Analog Comparator Interrupt Enable

When the ACIE bit is written logic one and the I-bit in the Status Register is set, the Ana-
log Comparator interrupt is activated. When written logic zero, the interrupt is disabled.

• Bit 2 – ACIC: Analog Comparator Input Capture Enable

When written logic one, this bit enables the Input Capture function in Timer/Counter1 to
be triggered by the Analog Comparator. The comparator output is in this case directly
connected to the Input Capture front-end logic, making the comparator utilize the noise
canceler and edge select features of the Timer/Counter1 Input Capture interrupt. When
written logic zero, no connection between the Analog Comparator and the Input Capture
function exists. To make the comparator trigger the Timer/Counter1 Input Capture inter-
rupt, the TICIE1 bit in the Timer Interrupt Mask Register (TIMSK) must be set.

• Bits 1, 0 – ACIS1, ACIS0: Analog Comparator Interrupt Mode Select

These bits determine which comparator events that trigger the Analog Comparator inter-
rupt. The different settings are shown in Table 82.

When changing the ACIS1/ACIS0 bits, the Analog Comparator Interrupt must be dis-
abled by clearing its Interrupt Enable bit in the ACSR Register. Otherwise an interrupt
can occur when the bits are changed.

Table 82. ACIS1/ACIS0 Settings

ACIS1

ACIS0

Interrupt Mode

0

0

Comparator Interrupt on Output Toggle.

0

1

Reserved

1

0

Comparator Interrupt on Falling Output Edge.

1

1

Comparator Interrupt on Rising Output Edge.