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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 29 | jimmy | 1 | /****************************************************************************** |
| 2 | * Copyright (C) 2005 Martin THOMAS, Kaiserslautern, Germany |
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| 3 | * <eversmith@heizung-thomas.de> |
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| 4 | * http://www.siwawi.arubi.uni-kl.de/avr_projects |
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| 5 | ***************************************************************************** |
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| 6 | * |
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| 7 | * File : timebase.c |
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| 8 | * Version : 0.9 |
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| 9 | * |
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| 10 | * Summary : AVR Timebase using Hardware-Timer 0 |
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| 11 | * |
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| 12 | *****************************************************************************/ |
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| 13 | |||
| 14 | #include <inttypes.h> |
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| 15 | #include <avr/io.h> |
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| 16 | #include <avr/interrupt.h> |
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| 17 | |||
| 18 | #include "timebase.h" |
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| 19 | |||
| 30 | jimmy | 20 | ISR(SIG_OVERFLOW0) |
| 29 | jimmy | 21 | { |
| 22 | gMilliSecTick++; |
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| 23 | TCNT0 = TIMEBASE_RELOAD; |
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| 24 | } |
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| 25 | |||
| 26 | void timebase_init(void) |
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| 27 | { |
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| 28 | TCCR0 = (1<<CS01) | (1<<CS00); // prescaler: 64 |
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| 29 | TCNT0 = TIMEBASE_RELOAD; // set initial reload-value |
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| 30 | TIFR |= (1<<TOV0); // clear overflow int. |
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| 31 | TIMSK |= (1<<TOIE0); // enable overflow-interrupt |
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| 32 | } |
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| 33 | |||
| 34 | uint16_t timebase_actTime(void) |
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| 35 | { |
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| 36 | uint8_t sreg; |
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| 37 | uint16_t res; |
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| 38 | |||
| 39 | sreg=SREG; |
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| 40 | cli(); |
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| 41 | |||
| 42 | res = gMilliSecTick; |
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| 43 | |||
| 44 | SREG=sreg; |
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| 45 | |||
| 46 | return res; |
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| 47 | } |
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| 48 | |||
| 49 | uint16_t timebase_passedTimeMS(uint16_t t0) |
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| 50 | { |
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| 51 | uint8_t sreg; |
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| 52 | uint16_t res; |
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| 53 | |||
| 54 | sreg=SREG; |
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| 55 | cli(); |
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| 56 | |||
| 57 | res = (uint16_t)(gMilliSecTick-t0); |
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| 58 | |||
| 59 | SREG=sreg; |
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| 60 | |||
| 61 | return res; |
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| 62 | } |
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| 63 | |||
| 64 |