As an electronics enthusiast or a hobbyist working with
microcontrollers, you may have come across the ATmega328 microcontroller, which is commonly used in Arduino boards. One of the
key features of the ATmega328 is its built-in timers - Timer0, Timer1,
and Timer2, which provide precise timing and counting capabilities for a
wide range of applications. In this blog post, we will delve into a
detailed comparison of these timers, exploring their functionalities,
modes of operation, and applications. Whether you are a beginner or an
experienced user, this comparison will help you understand the key
differences and choose the right timer for your project.
Comparison between Timer0, Timer1 and Timer2
| 8-bit timer/counter | 16-bit timer/counter | 8-bit timer/counter |
| Provides lesser precision timing compared to Timer1 | Provides higher precision timing compared to Timer0 and Timer2 | Provides lesser precision timing compared to Timer1 |
| No input capture unit | One input capture unit with Noise canceller | No input capture unit |
| 3 independent interrupt sources(TOV0, OCF0A, and OCF0B) | 4 independent interrupt sources(TOV1, OCF1A, OCF1B, and ICF1) | 3 independent interrupt sources (TOV2, OCF2A and OCF2B) |
| No External event counter | External event counter | No External event counter |
| N/A | N/A | Allows clocking from external 32kHz watch crystal independent of the I/O clock |
| Prescalar, N=1,8,64,256, or 1024 | Prescalar, N=1,8,64,256, or 1024 | 10-bit Clock prescaler, N=1, 8, 32, 64, 128, 256, or 1024 |
| Supports Normal, CTC, Fast and Phase Correct Mode | Supports Normal, CTC, Fast, Phase Correct Mode and Phase and Frequency Correct Mode | Supports Normal, CTC, Fast and Phase Correct Mode |
| OC0A=PD6 & OC0B=PD5 | OC1A=PB1 & OC1B=PB2 | OC2A=PB3 & OC2B=PD3 |
| Waveform Freq.: \(f_{OC0x} = \frac{f_{clk(I/O)}}{2N(1+OCR0x)} \) where,x=A or B |
Waveform Freq.: \(f_{OC1x} = \frac{f_{clk(I/O)}}{2N(1+OCR1x)} \) where,x=A or B |
Waveform Freq.: \(f_{OC2x} = \frac{f_{clk(I/O)}}{2N(1+OCR2x)} \) where,x=A or B |
| PWM Freq.: \(f_{OC0x} = \frac{f_{clk(I/O)}}{256N} \) where,x=A or B |
PWM Freq.: \(f_{OC1x} = \frac{f_{clk(I/O)}}{N(1+TOP)} \) where,x=A or B, TOP=OCR1A or ICR1 |
PWM Freq.: \(f_{OC2x} = \frac{f_{clk(I/O)}}{256N} \) where,x=A or B |
| PWM Freq.: \(f_{OC0x} = \frac{f_{clk(I/O)}}{510N} \) where,x=A or B Note:OC0A=PD6 & OC0B=PD5 |
PWM Freq.: \(f_{OC1x} = \frac{f_{clk(I/O)}}{2N(TOP)} \) where,x=A or B Note:OC1A=PB1 & OC1B=PB2, TOP=OCR1A or ICR1 |
PWM Freq.: \(f_{OC2x} = \frac{f_{clk(I/O)}}{510N} \) where,x=A or B Note:OC2A=PB3 & OC2B=PD3 |
| Examples: |
Examples: - |
Examples: - |
In summary, Timer0, Timer1, and Timer2 in ATmega328 offer different levels of precision, features, and capabilities, making them suitable for different timing and measurement tasks in embedded systems. The choice of timer depends on the specific requirements of the application and the desired level of precision and functionality needed. It is important to refer to the ATmega328 datasheet and timer-specific documentation for detailed information on their features, functionalities, and usage.
Tags:
ATmega328p
