Datasheet

19. TC1, 3, 4 - 16-bit Timer/Counter1, 3, 4 with PWM
19.1 Features
• Three 16-bit Timer/Counter instances TC1, TC3, TC4.
• 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
• Independent Interrupt Sources (TOV, OCFA, OCFB, and ICF)
19.2 Overview
The 16-bit Timer/Counter unit allows accurate program execution timing (event management), wave
generation, and signal timing measurement.
A block diagram of the 16-bit Timer/Counter is shown below. 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
Register Description. For the actual placement of I/O pins, refer to the Pin Configurations description.
Related Links
I/O-Ports
Pin Configurations
19.2.1 Definitions
Many register and bit references in this section are written in general form:
• n=1,3,4 represents the Timer/Counter number
• x=A,B represents the Output Compare Unit A or B
However, when using the register or bit definitions in a program, the precise form must be used, i.e.,
TCNT3 for accessing Timer/Counter 3 counter value.
The following definitions are used extensively throughout the section:
ATmega328PB
TC1, 3, 4 - 16-bit Timer/Counter1, 3, 4 with PWM
© 2018 Microchip Technology Inc.
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