atmega103 ATMEL Corporation, atmega103 Datasheet - Page 76

• Manufacturer Part Number: atmega103
• Description: Atmega103 8-bit With 128k Bytes Of In-system Programmable Flash
• Manufacturer: ATMEL Corporation

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ATmega103(L)
ing the corresponding interrupt handling vector. Alternatively, ACI is cleared by writing a
logical “1” to the flag. Observe, however, that if another bit in this register is modified
using the SBI or CBI instruction, ACI will be cleared if it has become set before the
operation.
• Bit 3 – ACIE: Analog Comparator Interrupt Enable
When the ACIE bit is set (one) and the I-bit in the Status Register is set (one), the Ana-
log Comparator interrupt is activated. When cleared (zero), the interrupt is disabled.
• Bit 2 – ACIC: Analog Comparator Input Capture Enable
When set (one), this bit enables the Input Capture function in Timer/Counter1 to be trig-
gered 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
cleared (zero), no connection between the analog comparator and the Input Capture
function is given. To make the comparator trigger the Timer/Counter1 Input Capture
interrupt, the TICIE1 bit in the Timer Interrupt Mask Register (TIMSK) must be set (one).
• 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 25.
Table 25. ACIS1/ACIS0 Settings
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.
Caution: Using the SBI or CBI instruction on other bits than ACI in this register will write
a one back into ACI if it is read as set, thus clearing the flag.
ACIS1
0
0
1
1
ACIS0
0
1
0
1
Comparator Interrupt on Output Toggle
Reserved
Comparator Interrupt on Falling Output Edge
Comparator Interrupt on Rising Output Edge
Interrupt Mode
0945I–AVR–02/07