ATMEga64L ATMEL Corporation, ATMEga64L Datasheet - Page 227

• Manufacturer Part Number: ATMEga64L
• Description: 8-bit AVR Microcontroller with 64K Bytes In-System Programmable Flash
• Manufacturer: ATMEL Corporation

Analog Comparator
Special Function IO Register –
SFIOR
2490G–AVR–03/04
The Analog Comparator compares the input values on the positive pin AIN0 and nega-
tive pin AIN1. When the voltage on the positive pin AIN0 is higher than the voltage on
the negative pin AIN1, the Analog Comparator output, ACO, is set. The comparator’s
output can be set to trigger the Timer/Counter1 Input Capture function. In addition, the
comparator can trigger a separate interrupt, exclusive to the Analog Comparator. The
user can select Interrupt triggering on comparator output rise, fall or toggle. A block dia-
gram of the comparator and its surrounding logic is shown in Figure 107.
Figure 107. Analog Comparator Block Diagram
Notes:
• 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 Compar-
ator. For a detailed description of this bit, see “Analog Comparator Multiplexed Input” on
page 229.
Bit
Read/Write
Initial Value
ADC MULTIPLEXER
REFERENCE
ACME
ADEN
BANDGAP
OUTPUT
1. See Table 94 on page 229.
2. Refer to Figure 1 on page 2 and Table 30 on page 72 for Analog Comparator pin
placement.
1)
TSM
R/W
ACBG
7
0
R
6
–
0
R
5
–
0
R
4
–
0
(1)(2)
ACME
R/W
3
0
PUD
R/W
2
0
ATmega64(L)
PSR2
R/W
1
0
PSR10
R/W
0
0
SFIOR
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