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Timer & Counter

91208102 Timer Counter

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Page 1: 91208102 Timer Counter

Timer & Counter

Page 2: 91208102 Timer Counter

Perbedaan Timer & Counter

• Timer dan Counter sebenarnya idektik, namun perbedaannya yaitu timer mencacah pulsa dari osilator, sedangkan counter mencacah keadaan tertentu.

Page 3: 91208102 Timer Counter

Timer/Counter AVR AtMega

• 8bit timer/counter0 dengan PWM• 16bit timer/counter 1• 8bit timer counter 2 dengan PWM dan

pengoperasian asinkron

Page 4: 91208102 Timer Counter

8bit timer/counter0 dengan PWM

• Clock timer counter dapat menggunakan sumber eksternal (T0) maupun internal tergantung pengaturan dari Timer/Counter Control Register (TCCR0).

• Register 8 bitnya terletak pada TCNT0 (Timer/Counter) dan OCR0 (Output Compare Register)

• Timer/counter dalam keadaan tidak aktif saaat tidak ada sumber clock yang dipilih

• Batas kemampuan mencacah dari 0 hingga 255

Page 5: 91208102 Timer Counter

Block Diagram

Page 6: 91208102 Timer Counter

Fitur

• Single Compare Unit Counter• Clear Timer on Compare Match (Auto Reload)• Glitch-free, Phase Correct Pulse Width

Modulator (PWM)• Frequency Generator• External Event Counter• 10-bit Clock Prescaler• Overflow and Compare Match Interrupt Sources

(TOV0 and OCF0)

Page 7: 91208102 Timer Counter

Mode Operasi

• Normal Mode– Paling simple, selalu increement, otomatis restart saat

mencacah maksimum(0xFF), • Clear Timer on Compare Match (CTC) Mode– Manipulasi resolusi counter pada OCR0, counter kembali

ke nol saat nilainya sama dengan OCR0, • Fast PWM Mode– Menawarkan pembangkitan PWM berfrekuensi tinggi

• Phase Correct PWM Mode– Menawarkan pembangkitan PWM beresolusi tinggi

Page 8: 91208102 Timer Counter

Register

• Bit 7 – FOCO : perbandingan kemampuan output

• Bit 3, 6 WGM01:0: Waveform Generation Mode• Bit 5:4 COM01:0: Compare Match Output

Mode• Bit 2:0 CS02:0: Clock Select• Bit 1 OCIE0: Timer/Counter0 Output Compare

Match Interrupt Enable

Page 9: 91208102 Timer Counter

16bit timer/counter 1

• Menggunaka Prosedur khusus saat mengakses 16 bit register

• Clock timer counter dapat menggunakan sumber eksternal (T1) maupun internal).

• Batas kemampuan mencacah dari 0 hingga 65535

• Memiliki mode tambahan Phase and Frequency Correct PWM mode

Page 10: 91208102 Timer Counter

Block Diagram

Page 11: 91208102 Timer Counter

Fitur• True 16-bit Design (that is, 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)

Page 12: 91208102 Timer Counter

Mode

• Normal Mode• Clear Timer on Compare Match (CTC) Mode• Fast PWM Mode• Phase Correct PWM Mode• Phase and Frequency Correct PWM mode

Page 13: 91208102 Timer Counter

Register A

• Bit 7:6 COM1A1:0: Compare Output Mode for Channel A

• Bit 5:4 COM1B1:0: Compare Output Mode for Channel B

• Bit 3 FOC1A: Force Output Compare for Channel A

• Bit 2 FOC1B: Force Output Compare for Channel B

• Bit 1:0 WGM11:0: Waveform Generation Mode

Page 14: 91208102 Timer Counter

Register B

• Bit 7 ICNC1: Input Capture Noise Canceler

• Bit 6 ICES1: Input Capture Edge Select• Bit 5 Reserved Bit• Bit 4:3 WGM13:2: Waveform Generation

Mode• Bit 2:0 CS12:0: Clock Select

Page 15: 91208102 Timer Counter

8bit timer/counter 2 dengan PWM dan pengoperasian asinkron

• Clock timer counter dapat menggunakan sumber eksternal (T2) maupun internal.

• Ataupun diatur secara asinkron melalui TOSC1/2 pin• Pengoperasian secara asinkron diatur oleh

Asynchronous Status Register (ASSR)• Register 8 bitnya terletak pada TCNT2

(Timer/Counter) dan OCR2 (Output Compare Register)

• Batas kemampuan mencacah dari 0 hingga 255

Page 16: 91208102 Timer Counter

Block Diagram

Page 17: 91208102 Timer Counter

Fitur

• Single Compare unit Counter• Clear Timer on Compare Match (Auto Reload)• Glitch-free, Phase Correct Pulse Width Modulator

(PWM)• Frequency Generator• 10-bit Clock Prescaler• Overflow and Compare Match Interrupt Sources (TOV2

and OCF2)• Allows clocking from External 32 kHz Watch Crystal

Independent of the I/O Clock

Page 18: 91208102 Timer Counter

Operasi Asinkron ASSR

• Bit 3 AS2: Asynchronous Timer/Counter2• Bit 2 TCN2UB: Timer/Counter2 Update

Busy• Bit 1 OCR2UB: Output Compare Register2

Update Busy• Bit 0 TCR2UB: Timer/Counter Control

Register2 Update Busy