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44 lines
877 B
C
44 lines
877 B
C
/*
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* Timer.c
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*
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* Created: 28/10/2021 17:51:29
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* Author: n0x
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*/
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#include <avr/io.h>
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#include <avr/interrupt.h>
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volatile uint16_t cntr = 0;
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void
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Timer_init (void){
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TCCR0A |= (1<<WGM01); /* Set WGM01 to high to enable CTC mode */
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TCCR0B |= (3<<CS00); /* Set the clock select bit to pre-scaler 3
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16MHz / 64 (pre-scaler 3) ==> 250KHz */
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TIMSK0 |= (1<<OCIE0A); /* Set OCIE0A to high to rise an interrupt when the counter matches OCR0A */
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OCR0A = 250 - 1; /* Set the Output Compare Register 0 A to 125 to trigger interrupt every 1ms
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16MHz / 64 (pre-scaler 3) / (250 ) ==> 1KHz (1ms) */
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/*
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For internal 1MHz clock:
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1MHz / 8 (pre-scaler 2) ==> 125 KHz
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1MHz / 8 (pre-scaler 2) / 125 (OCR) ==> 1 KHz (1ms)
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*/
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}
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uint16_t
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Timer_getTick(void){
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uint16_t tmp;
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cli();
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tmp = cntr;
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sei();
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return tmp;
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}
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ISR(TIMER0_COMPA_vect){
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cntr++;
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} |