Datasheet

ATmega48/88/168 Automotive [DATASHEET]
7530K–AVR–07/14
94
14. 16-bit Timer/Counter1 with PWM
The 16-bit Timer/Counter unit allows accurate program execution timing (event management), wave generation, and signal
timing measurement. The main features are:
● 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)
14.1 Overview
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 Figure 14-1 on page 95. For the actual placement of
I/O pins, refer to Section 1-1 “Pinout ATmega48/88/168” on page 3. 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
Section 14.10 “16-bit Timer/Counter Register Description” on page 113.
The PRTIM1 bit in Section 7.7.1 “Power Reduction Register - PRR” on page 35 must be written to zero to enable
Timer/Counter1 module.