ATmega32U4 Atmel Corporation, ATmega32U4 Datasheet - Page 139

• 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

15.2.1
15.2.2
7766F–AVR–11/10
Speed
Accuracy
Figure 15-1. Timer/Counter4 Block Diagram
The maximum speed of the Timer/Counter4 is 64 MHz. However, if a supply voltage below 4
volts is used, it is recommended to decrease the input frequency, because the Timer/Counter4
is not running fast enough on low voltage levels.
The Timer/Counter4 is a 10-bit Timer/Counter module that can alternatively be used as an 8-bit
Timer/Counter. The Timer/Counter4 registers are basically 8-bit registers, but on top of that
there is a 2-bit High Byte Register (TC4H) that can be used as a common temporary buffer to
access the two MSBs of the 10-bit Timer/Counter4 registers by the AVR CPU via the 8-bit data
bus, if the 10-bit accuracy is used. Whereas, if the two MSBs of the 10-bit registers are written to
zero the Timer/Counter4 is working as an 8-bit Timer/Counter. When reading the low byte of any
8-bit register the two MSBs are written to the TC4H register, and when writing the low byte of
any 8-bit register the two MSBs are written from the TC4H register. Special procedures must be
followed when accessing the 10-bit Timer/Counter4 values via the 8-bit data bus. These proce-
dures are described in the section
The Enhanced PWM mode allows to add a resolution bit to each Compare register A/B/D, while
the output frequency remains identical to a Normal PWM mode. That means that the TC4H reg-
ister contains one more bit that will be the MSB in a 11-bits enhanced PWM operation. See the
section
use it.
REGISTER (TIMSK4)
TOV4
T/C INT. MASK
TIMER/COUNTER4
(TCNT4)
8-BIT OUTPUT COMPARE
COMPARE REGISTER A
REGISTER A (OCR4A)
10-BIT COMPARATOR
10-BIT OUTPUT
“Enhanced Compare/PWM mode” on page 148
OCF4A
OCF4B
T/C INT. FLAG
REGISTER (TIFR4)
CLK
COUNT
CLEAR
DIRECTION
OCF4D
8-BIT OUTPUT COMPARE
REGISTER B (OCR4B)
COMPARE REGISTER B
10-BIT COMPARATOR
10-BIT OUTPUT
DEAD TIME GENERATOR
OC4A
REGISTER A (TCCR4A)
“Accessing 10-Bit Registers” on page
T/C CONTROL
8-BIT DATABUS
OC4A
8-BIT OUTPUT COMPARE
REGISTER C (OCR4C)
COMPARE REGISTER C
10-BIT COMPARATOR
10-BIT OUTPUT
DEAD TIME GENERATOR
T/C CONTROL
OC4B
REGISTER B (TCCR4B)
TIMER/COUNTER4 CONTROL LOGIC
for details about this feature and how to
OC4B
8-BIT OUTPUT COMPARE
COMPARE REGISTER D
REGISTER D (OCR4D)
10-BIT OUTPUT
10-BIT COMPARATOR
T/C CONTROL
REGISTER C (TCCR4C)
ATmega16/32U4
DEAD TIME GENERATOR
OC4D
159.
OC4D
2-BIT HIGH BYTE
REGISTER (TC4H)
T/C CONTROL
T/C CONTROL
REGISTER C (TCCR4D)
REGISTER D (TCCR4E)
FAULT_PROTECTION
139