Timer atau Counter Register – TCNT0

Sedangkan untuk Timer/Counter 16-bit blok diagramnya adalah sebagai berikut

Timer/Counter 16-bit memiliki fitur-fitur antara lain :

• 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)