ATmega32U4 Atmel Corporation, ATmega32U4 Datasheet - Page 311

• Manufacturer Part Number: ATmega32U4
• Manufacturer: Atmel Corporation

Specifications of ATmega32U4

• Flash (kbytes): 32 Kbytes
• Pin Count: 44
• Max. Operating Frequency: 16 MHz
• Cpu: 8-bit AVR
• # Of Touch Channels: 14
• Hardware Qtouch Acquisition: No
• Max I/o Pins: 26
• Ext Interrupts: 13
• Usb Transceiver: 1
• Usb Speed: Full Speed
• Usb Interface: Device
• Spi: 2
• Twi (i2c): 1
• Uart: 1
• Graphic Lcd: No
• Video Decoder: No
• Camera Interface: No
• Adc Channels: 12
• Adc Resolution (bits): 10
• Adc Speed (ksps): 15
• Analog Comparators: 1
• Resistive Touch Screen: No
• Temp. Sensor: Yes
• Crypto Engine: No
• Sram (kbytes): 3.3
• Eeprom (bytes): 1024
• Self Program Memory: YES
• Dram Memory: No
• Nand Interface: No
• Picopower: No
• Temp. Range (deg C): -40 to 85
• I/o Supply Class: 2.7 to 5.5
• Operating Voltage (vcc): 2.7 to 5.5
• Fpu: No
• Mpu / Mmu: no / no
• Timers: 4
• Output Compare Channels: 12
• Input Capture Channels: 2
• Pwm Channels: 8
• 32khz Rtc: No
• Calibrated Rc Oscillator: Yes

24.9.3
24.9.3.1
24.9.3.2
7766F–AVR–11/10
The ADC Data Register – ADCL and ADCH
ADLAR = 0
ADLAR = 1
Write on ADCSRA, a pending interrupt can be disabled. This also applies if the SBI and CBI
instructions are used.
• Bit 3 – ADIE: ADC Interrupt Enable
When this bit is written to one and the I-bit in SREG is set, the ADC Conversion Complete Inter-
rupt is activated.
• Bits 2:0 – ADPS2:0: ADC Prescaler Select Bits
These bits determine the division factor between the XTAL frequency and the input clock to the
ADC.
Table 24-5.
When an ADC conversion is complete, the result is found in these two registers. If differential
channels are used, the result is presented in two’s complement form.
When ADCL is read, the ADC Data Register is not updated until ADCH is read. Consequently, if
the result is left adjusted and no more than 8-bit precision (7 bit + sign bit for differential input
Bit
Bit
Read/Write
Initial Value
Bit
Bit
Read/Write
Initial Value
ADPS2
0
0
0
0
1
1
1
1
ADC7
ADC9
ADC1
ADC Prescaler Selections
15
15
R
R
R
R
–
7
0
0
7
0
0
ADC6
ADC8
ADC0
14
14
ADPS1
R
R
R
R
–
6
0
0
6
0
0
0
0
1
1
0
0
1
1
ADC5
ADC7
13
13
R
R
R
R
–
5
0
0
–
5
0
0
ADC4
ADC6
12
12
R
R
R
R
–
4
0
0
–
4
0
0
ADPS0
0
1
0
1
0
1
0
1
ADC3
ADC5
11
11
R
R
R
R
–
3
0
0
–
3
0
0
ADC2
ADC4
10
10
R
R
R
R
–
2
0
0
–
2
0
0
ADC9
ADC1
ADC3
Division Factor
ATmega16/32U4
R
R
R
R
9
1
0
0
9
–
1
0
0
128
16
32
64
2
2
4
8
ADC8
ADC0
ADC2
R
R
R
R
8
0
0
0
8
–
0
0
0
ADCH
ADCL
ADCH
ADCL
311