Rainbow Electronics ATtiny28L - Manual (Page 35)

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ATtiny28L/V
1062E–10/01
• Bit 2 – RES: Reserved Bit
This bit is a reserved bit in the ATtiny28 and will always read as zero.
• Bits 1, 0 - ACIS1, ACIS0: Analog Comparator Interrupt Mode Select
These bits determine which comparator events trigger the Analog Comparator Interrupt.
The different settings are shown in Table 16.
Note: 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 bits other than ACI in this register will write
a one back into ACI if it is read as set, thus clearing the flag.
Table 16. 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