//***************************************************************************////  File........: timer0.c////  Author(s)...: ATMEL Norway////  Target(s)...: ATmega169////  Compiler....: AVR-GCC 3.3.1; avr-libc 1.0////  Description.: AVR Butterfly Timer0 routines////  Revisions...: 1.0////  YYYYMMDD - VER. - COMMENT                                       - SIGN.////  20030116 - 1.0  - Created                                       - KS//  20031009          port to avr-gcc/avr-libc                      - M.Thomas////***************************************************************************//mtA//#include <inavr.h>//#include "iom169.h"#include <avr/io.h>#include <inttypes.h>#include <avr/signal.h>#include <avr/interrupt.h>//mtE#include "main.h"#include "types.h"#include "timer0.h"TIMER_CALLBACK_FUNC CallbackFunc[TIMER0_NUM_CALLBACKS];// Value definition:// 0      The timer has expired// 1-254  The timer is counting down// 255    Free timer// mt char CountDownTimers[TIMER0_NUM_COUNTDOWNTIMERS];uint8_t CountDownTimers[TIMER0_NUM_COUNTDOWNTIMERS];/*******************************************************************************   Function name : Timer0_Init**   Returns :       None**   Parameters :    None**   Purpose :       Initialize Timer/Counter 0******************************************************************************/void Timer0_Init(void){    //mt char i;	uint8_t i;    // Initialize array of callback functions    for (i=0; i<TIMER0_NUM_CALLBACKS; i++)        CallbackFunc[i] = NULL;    // Initialize countdown timers    for (i=0; i<TIMER0_NUM_COUNTDOWNTIMERS; i++)        CountDownTimers[i] = 255;	// Initialize Timer0.	// Used to give the correct time-delays in the song    // Enable timer0 compare interrupt	TIMSK0 = (1<<OCIE0A);    // Sets the compare value	OCR0A = 78;	// Set Clear on Timer Compare (CTC) mode, CLK/1024 prescaler	TCCR0A = (1<<WGM01)|(0<<WGM00)|(5<<CS00);		// (8000000/1024) / 78  = 100.16Hz or 9.984ms }/*******************************************************************************   Function name : TIMER0_COMP_interrupt**   Returns :       None**   Parameters :    None**   Purpose :       Check if any functions are to be called******************************************************************************/// mtA// #pragma vector = TIMER0_COMP_vect// __interrupt void TIMER0_COMP_interrupt(void)SIGNAL(SIG_OUTPUT_COMPARE0)// mtE{    // mt char i;	uint8_t i;        for (i=0; i<TIMER0_NUM_CALLBACKS; i++)        if (CallbackFunc[i] != NULL)            CallbackFunc[i]();        // Count down timers    for (i=0; i<TIMER0_NUM_COUNTDOWNTIMERS; i++)        if (CountDownTimers[i] != 255 && CountDownTimers[i] != 0)            CountDownTimers[i]--;}/*******************************************************************************   Function name : Timer0_RegisterCallbackFunction**   Returns :       None**   Parameters :    pFunc**   Purpose :       Set up functions to be called from the *                   TIMER0_COMP_interrupt******************************************************************************/BOOL Timer0_RegisterCallbackFunction(TIMER_CALLBACK_FUNC pFunc){    // mt char i;	uint8_t i;        for (i=0; i<TIMER0_NUM_CALLBACKS; i++)    {        if (CallbackFunc[i] == pFunc)            return TRUE;    }        for (i=0; i<TIMER0_NUM_CALLBACKS; i++)    {        if (CallbackFunc[i] == NULL)        {            CallbackFunc[i] = pFunc;            return TRUE;        }       }        return FALSE;}/*******************************************************************************   Function name : Timer0_RemoveCallbackFunction**   Returns :       None**   Parameters :    pFunc**   Purpose :       Remove functions from the list which is called int the*                   TIMER0_COMP_interrupt******************************************************************************/BOOL Timer0_RemoveCallbackFunction(TIMER_CALLBACK_FUNC pFunc){    // mt char i;	uint8_t i;        for (i=0; i<TIMER0_NUM_CALLBACKS; i++)    {        if (CallbackFunc[i] == pFunc)        {            CallbackFunc[i] = NULL;            return TRUE;        }    }            return FALSE;}char Timer0_AllocateCountdownTimer(){    // mt char i;	uint8_t i;	    for (i=0; i<TIMER0_NUM_COUNTDOWNTIMERS; i++)        if (CountDownTimers[i] == 255)        {            CountDownTimers[i] = 0;            return i+1;        }    return 0;}void Timer0_SetCountdownTimer(char timer, char value){    cli(); // mt __disable_interrupt();    CountDownTimers[timer-1] = value;    sei(); // mt __enable_interrupt();}char Timer0_GetCountdownTimer(char timer){    char t;    cli(); // mt __disable_interrupt();    t = CountDownTimers[timer-1];    sei(); // mt __enable_interrupt();        return t;}void Timer0_ReleaseCountdownTimer(char timer){    cli(); // mt __disable_interrupt();    CountDownTimers[timer-1] = 255;    sei(); // mt __enable_interrupt();}