ATmega32U4 Atmel Corporation, ATmega32U4 Datasheet - Page 109

• 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

14.1.1
7766F–AVR–11/10
Registers
Figure 14-1. 16-bit Timer/Counter Block Diagram
Note:
The Timer/Counter (TCNTn), Output Compare Registers (OCRnA/B/C), and Input Capture Reg-
ister (ICRn) are all 16-bit registers. Special procedures must be followed when accessing the 16-
bit registers. These procedures are described in the section
page
CPU access restrictions. Interrupt requests (shorten as Int.Req.) signals are all visible in the
Timer Interrupt Flag Register (TIFRn). All interrupts are individually masked with the Timer Inter-
rupt Mask Register (TIMSKn). TIFRn and TIMSKn are not shown in the figure since these
registers are shared by other timer units.
The Timer/Counter can be clocked internally, via the prescaler, or by an external clock source on
the Tn pin. The Clock Select logic block controls which clock source and edge the Timer/Counter
uses to increment (or decrement) its value. The Timer/Counter is inactive when no clock source
is selected. The output from the clock select logic is referred to as the timer clock (clk
110. The Timer/Counter Control Registers (TCCRnA/B/C) are 8-bit registers and have no
1. Refer to
2. Tn only refers to T1 since T3 input is not available on the ATmega16U4/ATmega32U4
10-6 on page 75
product
.
“Pinout ATmega16U4/ATmega32U4” on page
Timer/Counter
OCRnB
TCCRnA
for Timer/Counter1 and 3 and 3 pin placement and description.
OCRnA
OCRnC
TCNTn
ICRn
=
=
=
Direction
Count
Clear
Control Logic
TOP
=
TCCRnB
Values
BOTTOM
Fixed
TOP
(1)
ICFn (Int.Req.)
TCLK
Detector
Edge
=
0
3,
“Accessing 16-bit Registers” on
Table 10-3 on page
ATmega16/32U4
OCFnA
(Int.Req.)
OCFnB
(Int.Req.)
OCFnC
(Int.Req.)
TOVn
(Int.Req.)
Clock Select
Generation
Generation
Generation
( From Prescaler )
Waveform
Waveform
Waveform
TCCRnC
Canceler
Detector
Noise
Edge
Comparator Ouput )
( From Analog
72, and
OCnA
OCnB
OCnC
ICPn
Tn
(2)
T
n
).
Table
109