ATmega32U4 Atmel Corporation, ATmega32U4 Datasheet - Page 162

• 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

15.12 Register Description
15.12.1
7766F–AVR–11/10
TCCR4A – Timer/Counter4 Control Register A
• Bits 7,6 - COM4A1, COM4A0: Comparator A Output Mode, Bits 1 and 0
These bits control the behavior of the Waveform Output (OCW4A) and the connection of the
Output Compare pin (OC4A). If one or both of the COM4A1:0 bits are set, the OC4A output
overrides the normal port functionality of the I/O pin it is connected to. The complementary
OC4B output is connected only in PWM modes when the COM4A1:0 bits are set to “01”. Note
that the Data Direction Register (DDR) bit corresponding to the OC4A and OC4A pins must be
set in order to enable the output driver.
The function of the COM4A1:0 bits depends on the PWM4A, WGM40 and WGM41 bit settings.
Table 15-6
(non-PWM).
Table 15-6.
Table 15-7
are set to fast PWM mode.
Table 15-7.
Bit
Read/Write
Initial value
COM4A1..0
COM4A1..0
00
01
10
11
00
01
10
11
shows the COM4A1:0 bit functionality when the PWM4A, WGM40 and WGM41 bits
shows the COM4A1:0 bit functionality when the PWM4A bit is set to Normal Mode
COM4A1
Compare Output Mode, Normal Mode (non-PWM)
Compare Output Mode, Fast PWM Mode
R/W
OCW4A Behavior
Normal port operation.
Toggle on Compare Match.
Clear on Compare Match.
Set on Compare Match.
OCW4A Behavior
Normal port operation.
Cleared on Compare Match.
Set when TCNT4 = 0x000.
Cleared on Compare Match.
Set when TCNT4 = 0x000.
Set on Compare Match.
Cleared when TCNT4 = 0x000.
7
0
COM4A0
R/W
6
0
COM4B1
R/W
5
0
COM4B0
R/W
4
0
FOC4A
W
3
0
FOC4B
W
2
0
ATmega16/32U4
Disconnected
Disconnected
Connected
Connected
Connected
Connected
Connected
Connected
OC4A Pin
OC4A
PWM4A
R/W
1
0
PWM4B
R/W
0
0
Disconnected
Disconnected
Disconnected
Disconnected
Disconnected
Disconnected
Disconnected
Connected
OC4A Pin
OC4A
TCCR4A
162