Datasheet

27.3.1. SFIOR – Analog Comparator Control and Status Register
When using the I/O specific commands IN and OUT, the I/O addresses 0x00 - 0x3F must be used. When
addressing I/O Registers as data space using LD and ST instructions, 0x20 must be added to these offset
addresses. The device is a complex microcontroller with more peripheral units than can be supported
within the 64 location reserved in Opcode for the IN and OUT instructions. For the Extended I/O space
from 0x60 in SRAM, only the ST/STS/STD and LD/LDS/LDD instructions can be used.
Name: SFIOR
Offset: 0x20
Reset: N/A
Property: When addressing I/O Registers as data space the offset address is 0x40
Bit 7 6 5 4 3 2 1 0
ACME
Access
R/W
Reset 0
Bit 3 – ACME: Analog Comparator Multiplexer Enable
When this bit is written logic one and the ADC is switched off (ADEN in ADCSRA is zero), the ADC
multiplexer selects the negative input to the Analog Comparator. When this bit is written logic zero, AIN1
is applied to the negative input of the Analog Comparator. For a detailed description of this bit, see
Analog Comparator Multiplexed Input on page 306.
Atmel ATmega64A [DATASHEET]
Atmel-8160E-ATmega64A_Datasheet_Complete-09/2015
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