ATmega32U4 Atmel Corporation, ATmega32U4 Datasheet - Page 312

• 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

24.9.4
7766F–AVR–11/10
ADC Control and Status Register B – ADCSRB
channels) is required, it is sufficient to read ADCH. Otherwise, ADCL must be read first, then
ADCH.
The ADLAR bit in ADMUX, and the MUXn bits in ADMUX affect the way the result is read from
the registers. If ADLAR is set, the result is left adjusted. If ADLAR is cleared (default), the result
is right adjusted.
• ADC9:0: ADC Conversion Result
These bits represent the result from the conversion, as detailed in
page
• Bit 7 – ADHSM: ADC High Speed Mode
Writing this bit to one enables the ADC High Speed mode. This mode enables higher conversion
rate at the expense of higher power consumption.
• Bit 5 – MUX5: Analog Channel Additional Selection Bits
This bit make part of MUX5:0 bits of ADRCSRB and ADMUX register, that select the combina-
tion of analog inputs connected to the ADC (including differential amplifier configuration).
• Bit 3:0 – ADTS3:0: ADC Auto Trigger Source
If ADATE in ADCSRA is written to one, the value of these bits selects which source will trigger
an ADC conversion. If ADATE is cleared, the ADTS3:0 settings will have no effect. A conversion
will be triggered by the rising edge of the selected interrupt flag. Note that switching from a trig-
ger source that is cleared to a trigger source that is set, will generate a positive edge on the
trigger signal. If ADEN in ADCSRA is set, this will start a conversion. Switching to Free Running
mode (ADTS[3:0]=0) will not cause a trigger event, even if the ADC Interrupt Flag is set
Table 24-6.
Bit
Read/Write
Initial Value
ADTS3
305.
0
0
0
0
0
0
0
0
1
ADHSM
ADC Auto Trigger Source Selections
R/W
7
0
ADTS2
0
0
0
0
1
1
1
1
0
ACME
R/W
6
0
MUX5
R
5
0
ADTS1
0
0
1
1
0
0
1
1
0
R
4
–
0
ADTS3
ADTS0
R
3
0
0
1
0
1
0
1
0
1
0
ADTS2
R/W
2
0
Trigger Source
Free Running mode
Analog Comparator
External Interrupt Request 0
Timer/Counter0 Compare Match
Timer/Counter0 Overflow
Timer/Counter1 Compare Match B
Timer/Counter1 Overflow
Timer/Counter1 Capture Event
Timer/Counter4 Overflow
ADTS1
R/W
ATmega16/32U4
1
0
“ADC Conversion Result” on
ADTS0
R/W
0
0
ADCSRB
.
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