ATMEGA64A-AU Atmel, ATMEGA64A-AU Datasheet - Page 247

• Manufacturer Part Number: ATMEGA64A-AU
• Description: MCU AVR 64K ISP FLASH 64-TQFP
• Manufacturer: Atmel
• Series: AVR® ATmegar

Specifications of ATMEGA64A-AU

• Core Processor: AVR
• Core Size: 8-Bit
• Speed: 16MHz
• Connectivity: I²C, SPI, UART/USART
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 53
• 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): 2.7 V ~ 5.5 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 64-TQFP, 64-VQFP
• Package: 64TQFP
• Device Core: AVR
• Family Name: ATmega
• Maximum Speed: 16 MHz
• Operating Supply Voltage: 3.3|5 V
• Data Bus Width: 8 Bit
• Number Of Programmable I/os: 53
• Interface Type: SPI/USART
• On-chip Adc: 8-chx10-bit
• Number Of Timers: 4
• Processor Series: ATMEGA64x
• Core: AVR8
• Data Ram Size: 4 KB
• Maximum Clock Frequency: 16 MHz
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• 3rd Party Development Tools: EWAVR, EWAVR-BL
• Development Tools By Supplier: ATAVRDRAGON, ATSTK500, ATSTK600, ATAVRISP2, ATAVRONEKIT
• Minimum Operating Temperature: - 40 C
• Cpu Family: ATmega
• Device Core Size: 8b
• Frequency (max): 16MHz
• Total Internal Ram Size: 4KB
• # I/os (max): 53
• Number Of Timers - General Purpose: 4
• Operating Supply Voltage (typ): 3.3/5V
• Operating Supply Voltage (max): 5.5V
• Operating Supply Voltage (min): 2.7V
• Instruction Set Architecture: RISC
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 64
• Package Type: TQFP
• For Use With: 770-1007 - ISP 4PORT ATMEL AVR MCU SPI/JTAG
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

23.9
23.9.1
8160C–AVR–07/09
Register Description
ADMUX – ADC Multiplexer Selection Register
Table 23-2.
Example:
ADMUX = 0xED (ADC3 - ADC2, 10x gain, 2.56V reference, left adjusted result).
Voltage on ADC3 is 300 mV, voltage on ADC2 is 500 mV.
ADCR = 512 * 10 * (300 - 500) / 2560 = -400 = 0x270.
ADCL will thus read 0x00, and ADCH will read 0x9C. Writing zero to ADLAR right adjusts the
result: ADCL = 0x70, ADCH = 0x02.
• Bit 7:6 – REFS1:0: Reference Selection Bits
These bits select the voltage reference for the ADC, as shown in
changed during a conversion, the change will not go in effect until this conversion is complete
(ADIF in ADCSRA is set). The internal voltage reference options may not be used if an external
reference voltage is being applied to the AREF pin.
Table 23-3.
Bit
0x07 (0x27)
Read/Write
Initial Value
V
V
V
:.
V
V
V
:.
V
V
V
REFS1
ADCn
ADCm
ADCm
ADCm
ADCm
ADCm
ADCm
ADCm
ADCm
0
0
1
1
+ 511/512 V
+ 510/512 V
+ 1/512 V
- 1/512 V
- 511/512V
- V
+ V
REF
REF
REFS0
/GAIN
/GAIN
REFS1
Correlation Between Input Voltage and Output Codes
Voltage Reference Selections for ADC
R/W
0
1
0
1
REF
REF
7
0
REF
REF
REF
/GAIN
/GAIN
/GAIN
/GAIN
/GAIN
Voltage Reference Selection
AREF, Internal Vref turned off.
AVCC with external capacitor at AREF pin.
Reserved
Internal 2.56V Voltage Reference with external capacitor at AREF pin.
REFS0
R/W
6
0
ADLAR
R/W
5
0
Read Code
0x1FF
0x1FF
0x1FE
:.
0x001
0x000
0x3FF
:.
0x201
0x200
MUX4
R/W
4
0
MUX3
R/W
3
0
MUX2
Corresponding Decimal Value
R/W
2
0
Table
MUX1
R/W
1
0
ATmega64A
-511
-512
511
511
510
23-3. If these bits are
-1
:.
1
0
:.
MUX0
R/W
0
0
ADMUX
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