Datasheet

21. 16-bit Timer/Counter1

21.1 Features

• True 16-bit Design (i.e., allows 16-bit PWM)

• Two independent Output Compare Units

• Double Buffered Output Compare Registers

• One Input Capture Unit

• Input Capture Noise Canceler

• Clear Timer on Compare Match (Auto Reload)

• Glitch-free, Phase Correct Pulse Width Modulator (PWM)

• Variable PWM Period

• Frequency Generator

• External Event Counter

• Four independent interrupt Sources (TOV1, OCF1A, OCF1B, and ICF1)

21.2 Overview

The 16-bit Timer/Counter unit allows accurate program execution timing (event management), wave

generation, and signal timing measurement. Most register and bit references in this section are written in

general form. A lower case “n” replaces the Timer/Counter number, and a lower case “x” replaces the

Output Compare unit channel. However, when using the register or bit defines in a program, the precise

form must be used i.e., TCNT1 for accessing Timer/Counter1 counter value and so on.

A simplified block diagram of the 16-bit Timer/Counter is shown in the following figure. For the actual

placement of I/O pins, refer to Pin Configurations. CPU accessible I/O Registers, including I/O bits and

I/O pins, are shown in bold. The device-specific I/O Register and bit locations are listed in the Register

Description.

AVR 8-Bit Microcontroller

16-bit Timer/Counter1

Datasheet Complete

40001974A-page 114