ATMEGA649A-AU Atmel, ATMEGA649A-AU Datasheet - Page 216

• Manufacturer Part Number: ATMEGA649A-AU
• Description: IC MCU AVR 64K FLASH 64TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA649A-AU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: SPI, UART/USART, USI
• Peripherals: Brown-out Detect/Reset, LCD, POR, PWM, WDT
• Number Of I /o: 54
• Program Memory Size: 64KB (32K x 16)
• Program Memory Type: FLASH
• Eeprom Size: 2K x 8
• Ram Size: 4K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-TQFP
• Processor Series: ATmega
• Core: AVR
• Data Bus Width: 8 bit
• Data Ram Size: 4 KB
• Interface Type: SPI, USART
• Maximum Clock Frequency: 16 MHz
• Number Of Programmable I/os: 54
• Number Of Timers: 3
• Operating Supply Voltage: 3.3 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Operating Temperature Range: - 40 C to + 85 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

21. Analog Comparator
21.1
21.2
8284A–AVR–10/10
Overview
Analog Comparator Multiplexed Input
The Analog Comparator compares the input values on the positive pin AIN0 and negative 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 com-
parator output rise, fall or toggle. A block diagram of the comparator and its surrounding logic is
shown in
The PRADC, in
the ADC input MUX.
Figure 21-1. Analog Comparator Block Diagram
Note:
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 on page
Analog Comparator.
Table 21-1.
ATmega169A/169PA/329A/329PA/649A/649P/3290A/3290PA/6490A/6490P
ACME
0
1
1
ADC MULTIPLEXER
1. See
2. Refer to
Figure
REFERENCE
ACME
ADEN
BANDGAP
OUTPUT
placement.
216. If ACME is cleared or ADEN is set, AIN1 is applied to the negative input to the
Analog Comparator Multiplexed Input
Table 21-1 on page
(1)
”PRR – Power Reduction Register” on page 46
21-1.
ADEN
ACBG
1
0
”Pin Configurations” on page 2
x
MUX2:0
000
xxx
xxx
216.
Analog Comparator Negative Input
AIN1
AIN1
ADC0
and
(2)
Table 13-5 on page 75
must be written to zero to use
for Analog Comparator pin
Table
216