ATMEGA649A-AU Atmel, ATMEGA649A-AU Datasheet - Page 231

• 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

8284A–AVR–10/10
Figure 22-14. Differential Measurement Range
Table 22-2.
ADMUX = 0xFB (ADC3 - ADC2, 1.1V reference, left adjusted result)
Voltage on ADC3 is 300 mV, voltage on ADC2 is 500 mV.
ADCR = 512 * (300 - 500) / 1100 = -93 = 0x3A3.
ADCL will thus read 0xC0, and ADCH will read 0xD8. Writing zero to ADLAR right adjusts the
result: ADCL = 0xA3, ADCH = 0x03.
V
V
V
...
V
V
V
...
V
V
V
ATmega169A/169PA/329A/329PA/649A/649P/3290A/3290PA/6490A/6490P
ADCn
ADCm
ADCm
ADCm
ADCm
ADCm
ADCm
ADCm
ADCm
+
+
+
-
-
- V
+ V
1
511
511
510
1
- V
/
/
512
REF
512
/
REF
REF
/
/
512
512
512
V
V
REF
V
Correlation Between Input Voltage and Output Codes
REF
V
V
REF
REF
REF
Read Code
0x1FF
0x1FF
0x1FE
...
0x001
0x000
0x3FF
...
0x201
0x200
Output Code
0x3FF
0x1FF
0x000
0x200
0
Corresponding Decimal Value
V
-511
-512
511
511
510
REF
...
-1
...
1
0
Differential Input
Voltage (Volts)
231