ATmega32U4 Atmel Corporation, ATmega32U4 Datasheet - Page 264

• 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

7766F–AVR–11/10
• 5 – FRZCLK: Freeze USB Clock Bit
Set to disable the clock inputs (the ”Resume Detection” is still active). This reduces the power
consumption. Clear to enable the clock inputs.
• 4 – OTGPADE: VBUS Pad Enable
Set to enable the VBUS pad. Clear to disable the VBUS pad.
Note that this bit can be set/cleared even if USBE=0. That allows the VBUS detection even if the
USB macro is disable.
• 3-1 – Reserved
The value read from these bits is always 0. Do not set these bits.
• 0 – VBUSTE: VBUS Transition Interrupt Enable Bit
Set this bit to enable the VBUS Transition interrupt generation.
Clear this bit to disable the VBUS Transition interrupt generation.
• 7-2 - Reserved
The value read from these bits is always 0. Do not set these bits.
• 1 - ID: ID status
This bit is always read as “1”, it has been conserved for compatibility with AT90USB64/128 (in
which it indicates the value of the OTG ID pin).
• 0 – VBUS: VBus Flag
The value read from this bit indicates the state of the VBUS pin. This bit can be used in device
mode to monitor the USB bus connection state of the application. See Section 21.11, page 262
for more details.
7-1 - Reserved
The value read from these bits is always 0. Do not set these bits.
• 0 – VBUSTI: IVBUS Transition Interrupt Flag
Set by hardware when a transition (high to low, low to high) has been detected on the VBUS
pad.
Shall be cleared by software.
Bit
Read/Write
Initial Value
Bit
Read/Write
Initial Value
R
7
0
R
-
7
0
-
R
6
0
-
R
6
0
-
R
5
0
-
R
5
0
-
R
4
0
-
R
4
0
-
R
3
0
-
R
3
0
-
R
2
0
-
R
2
0
-
ATmega16/32U4
ID
R
1
1
R/W
1
0
-
VBUS
VBUSTI
R
0
0
R/W
0
0
USBSTA
USBINT
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