ATMEGA640 datasheet(133/436 Pages) MICROCHIP

133 / 436 page

133

ATmega640/V-1280/V-1281/V-2560/V-2561/V [DATASHEET]

DS40002211A

17. 16-bit Timer/Counter (Timer/Counter 1, 3, 4, and 5)

17.1 Features

• True 16-bit Design (that is, allows 16-bit PWM)

• Three 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

• Twenty independent interrupt sources (TOV1, OCF1A, OCF1B, OCF1C, ICF1, TOV3, OCF3A, OCF3B, OCF3C, ICF3,

TOV4, OCF4A, OCF4B, OCF4C, ICF4, TOV5, OCF5A, OCF5B, OCF5C, and ICF5)

17.2 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

counter value and so on.

A simplified block diagram of the 16-bit Timer/Counter is shown in Figure 17-1 on page 134. For the actual place-

ment of I/O pins, see “TQFP-pinout ATmega640/1280/2560” on page 2 and “Pinout ATmega1281/2561” on page

4. CPU accessible I/O Registers, including I/O bits and I/O pins, are shown in bold. The device-specific I/O Regis-

ter and bit locations are listed in the “Register Description” on page 154.

The Power Reduction Timer/Counter1 bit, PRTIM1, in “PRR0 – Power Reduction Register 0” on page 55 must be

written to zero to enable Timer/Counter1 module.

The Power Reduction Timer/Counter3 bit, PRTIM3, in “PRR1 – Power Reduction Register 1” on page 56 must be

written to zero to enable Timer/Counter3 module.

The Power Reduction Timer/Counter4 bit, PRTIM4, in “PRR1 – Power Reduction Register 1” on page 56 must be

written to zero to enable Timer/Counter4 module.

The Power Reduction Timer/Counter5 bit, PRTIM5, in “PRR1 – Power Reduction Register 1” on page 56 must be

written to zero to enable Timer/Counter5 module.

Timer/Counter4 and Timer/Counter5 only have full functionality in the ATmega640/1280/2560. Input capture and

output compare are not available in the ATmega1281/2561.

ATMEGA640 датащи(PDF) 133 Page - Microchip Technology