ATMEGA3250-16AUR Atmel, ATMEGA3250-16AUR Datasheet - Page 198

• Manufacturer Part Number: ATMEGA3250-16AUR
• Description: MCU AVR 32K FLASH 16MHZ 100TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA3250-16AUR

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: SPI, UART/USART, USI
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 69
• Program Memory Size: 32KB (16K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 1K x 8
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: *
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

21.1
21.2
21.2.1
21.2.2
2570M–AVR–04/11
Analog Comparator Multiplexed Input
Register Description
ADCSRB – ADC Control and Status Register B
ACSR – Analog Comparator Control and Status Register
It is possible to select any of the ADC7..0 pins to replace the negative input to the Analog Com-
parator. The ADC multiplexer is used to select this input, and consequently, the ADC must be
switched off to utilize this feature. If the Analog Comparator Multiplexer Enable bit (ACME in
ADCSRB) is set and the ADC is switched off (ADEN in ADCSRA is zero), MUX2..0 in ADMUX
select the input pin to replace the negative input to the Analog Comparator, as shown in
21-1. If ACME is cleared or ADEN is set, AIN1 is applied to the negative input to the Analog
Comparator.
Table 21-1.
• Bit 6 – 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
Bit
(0x7B)
Read/Write
Initial Value
Bit
0x30 (0x50)
Read/Write
Initial Value
ACME
0
1
1
1
1
1
1
1
1
1
Analog Comparator Multiplexed Input
ACD
ADEN
R/W
R
7
0
7
–
0
1
0
0
0
0
0
0
0
0
x
ACBG
ACME
R/W
R/W
6
0
6
0
“DIDR1 – Digital Input Disable Register 1” on page
MUX2..0
000
001
010
011
100
101
110
111
xxx
xxx
ACO
N/A
R
5
R
5
–
0
Analog Comparator Negative Input
AIN1
AIN1
ADC0
ADC1
ADC2
ADC3
ADC4
ADC5
ADC6
ADC7
R/W
ACI
4
0
R
4
–
0
ATmega325/3250/645/6450
ACIE
R/W
3
0
R
3
–
0
ADTS2
ACIC
R/W
R/W
2
0
2
0
ACIS1
ADTS1
R/W
R/W
1
0
1
0
ACIS0
ADTS0
R/W
R/W
0
0
0
0
200.
ADCSRB
ACSR
Table
198