Datasheet

ATmega16U4/32U4 [DATASHEET]

Atmel-7766J-USB-ATmega16U4/32U4-Datasheet_04/2016

15. 10-bit High Speed Timer/Counter4

15.1 Features

• Up to 10-Bit Accuracy

• Three Independent Output Compare Units

• Clear Timer on Compare Match (Auto Reload)

• Glitch Free, Phase and Frequency Correct Pulse Width Modulator (PWM)

• Enhanced PWM mode: one optional additional accuracy bit without effect on output frequency

• Variable PWM Period

• Independent Dead Time Generators for each PWM channels

• Synchronous update of PWM registers

• Five Independent Interrupt Sources (TOV4, OCF4A, OCF4B, OCF4D, FPF4)

• High Speed Asynchronous and Synchronous Clocking Modes

• Separate Prescaler Unit

15.2 Overview

Timer/Counter4 is a general purpose high speed Timer/Counter module, with three independent Output

Compare Units, and with enhanced PWM support.

The Timer/Counter4 features a high resolution and a high accuracy usage with the lower prescaling

opportunities. It can also support three accurate and high speed Pulse Width Modulators using clock speeds up

to 64MHz. In PWM mode Timer/Counter4 and the output compare registers serve as triple stand-alone PWMs

with non-overlapping, non-inverted and inverted outputs. The enhanced PWM mode allows to get one more

accuracy bit while keeping the frequency identical to normal mode (a PWM 8 bits accuracy in enhanced mode

outputs the same frequency that a PWM 7 bits accuracy in normal mode). Similarly, the high prescaling

opportunities make this unit useful for lower speed functions or exact timing functions with infrequent actions. A

lock feature allows user to update the PWM registers and

A simplified block diagram of the Timer/Counter4 is shown in Figure 15-1 on page 141. For actual placement of

the I/O pins, refer to “Pinout” on page 3. The device-specific I/O register and bit locations are listed in the

“Register Description” on page 164.