// Set up PWM on the given pin
boolean pwmInitDeciHertz(const IOPin* pin, uint32_t deciHertz, PERCENTAGE duty, uint32_t* actualDeciHertz){
boolean rtn = FALSE;
const TimerCompare* channel = compareFromIOPin(pin);
if(channel==null){
setError(PWM_PIN_NOT_AVAILABLE);
}else{
// The pin is valid
// The pin is valid and available
TIMER_MODE mode;
uint16_t icr;
uint16_t prescaler;
uint32_t actual;
const Timer* timer = compareGetTimer(channel);
// Find the best PWM setting
boolean valid = timerCalcPwm(timer, deciHertz, 100, &mode, &icr, &prescaler, &actual);
if(!valid){
// There is no PWM setting that is valid
setError( (timerIsInUse(timer)) ? PWM_TIMER_IN_USE : TIMER_HAS_NO_PWM );
}else{
// Lets set up the PWM
timerSetMode(timer,mode);
if(modeIsICR(mode)){
// Set the ICR
PORT icrPort = pgm_read_word(&timer->pgm_icr);
_SFR_MEM16(icrPort)=icr;
}
// Mark the channel as in use
// compareAttach(channel,&nullTimerCompareCallback,0,null);
// Turn the pin into an output, low
pin_make_output(pin, FALSE);
// Turn on the PWM pin output
compareSetOutputMode(channel, CHANNEL_MODE_NON_INVERTING);
// Turn on the timer
timerSetPrescaler(timer,prescaler);
// Set the initial duty cycle
pwmSetDutyCycle(pin,duty);
// Set the return value
if(actualDeciHertz){
*actualDeciHertz = actual;
}
rtn = TRUE;
}
}
return rtn;
}
// Author: unknown // Modified by : Markus Joos ([email protected]) #include <avr/io.h> #include <avr/interrupt.h> #include <avr/pgmspace.h> #include <avr/sleep.h> #include "global.h" #include "timer.h" // Program ROM constants // the pre-scale division values stored in order of timer control register index // STOP, CLK, CLK/8, CLK/64, CLK/256, CLK/1024 unsigned short __attribute__ ((progmem)) const TimerPrescaleFactor[] = {0,1,8,64,256,1024}; typedef void (*voidFuncPtr)(void); volatile static voidFuncPtr TimerIntFunc; // Delay for a minimum of <us> microseconds // The time resolution is dependent on the time the loop takes // e.g. with 4Mhz and 5 cycles per loop, the resolution is 1.25 us //***********************/ void delay_us(u16 time_us) //Called from ipmi_if.c and fru.c //***********************/ { u16 delay_loops; register u16 i; // one loop takes 5 cpu cycles delay_loops = (time_us + 3) / 22 * 3 * CYCLES_PER_US; // +3 for rounding up (dirty) //MJ: "22 * 3" is the result of a manual calibration of the delay for (i=0; i < delay_loops; i++) asm volatile("nop"); //MJ: Without the "nop" there is the risk that the loop gets removed by the optimizer } //*****************/ void timerInit(void) //Called from mmc_main.c //*****************/ { TimerIntFunc = 0; // detach all user functions from interrupts // Initialise timer 0 outb(TCCR0, (inb(TCCR0) | CTC_MODE)); // set set CTC mode timerSetPrescaler(TIMER0PRESCALE); // set pre-scaler outb(TCNT0, 0); // reset TCNT0 outb(OCR0, 0x8C); // set value to output compare register sbi(TIMSK, OCIE0); // enable output compare match interrupt }
static boolean initPWM(const IOPin* pin, uint32_t deciHertz){
const TimerCompare* channel = compareFromIOPin(pin);
if(channel==null){
setError(PWM_PIN_NOT_AVAILABLE);
return FALSE;
}
if(compareIsInUse(channel)){
setError(PWM_PIN_IN_USE);
return FALSE;
}
TIMER_MODE mode;
uint16_t icr;
uint16_t prescaler;
const Timer* timer = compareGetTimer(channel);
// Find the best PWM setting for 10kHz, with 128 steps
boolean valid = timerCalcPwm(timer, deciHertz, 128, &mode, &icr, &prescaler);
if(!valid){
// There is no PWM setting that is valid
setError( (timerIsInUse(timer)) ? PWM_TIMER_IN_USE : TIMER_HAS_NO_PWM );
}else{
// Lets set up the PWM
if(!timerIsInUse(timer)){
timerSetMode(timer,mode);
if(modeIsICR(mode)){
// Set the ICR
PORT icrPort = pgm_read_word(&timer->pgm_icr);
_SFR_MEM16(icrPort)=icr;
}
}
// Make it an output pin and set high for brake
pin_make_output(pin,TRUE);
// Use inverting PWM
compareSetOutputMode(channel,CHANNEL_MODE_INVERTING);
// Mark the channels as in use
compareAttach(channel,&nullTimerCompareCallback,0,null);
// Do this last as it then turns on the timer
timerSetPrescaler(timer,prescaler);
}
return valid;
}
/*
void delay_ms(unsigned char time_ms)
{
unsigned short delay_count = F_CPU / 4000;
unsigned short cnt;
asm volatile ("\n"
"L_dl1%=:\n\t"
"mov %A0, %A2\n\t"
"mov %B0, %B2\n"
"L_dl2%=:\n\t"
"sbiw %A0, 1\n\t"
"brne L_dl2%=\n\t"
"dec %1\n\t" "brne L_dl1%=\n\t":"=&w" (cnt)
:"r"(time_ms), "r"((unsigned short) (delay_count))
);
}
*/
void timerInit(void)
{
// detach all user functions from interrupts
TimerIntFunc = 0;
// initialize timer 0
outb(TCCR0, (inb(TCCR0) | CTC_MODE)); // set set CTC mode
timerSetPrescaler( TIMER0PRESCALE ); // set prescaler
// timerSetPrescaler( TIMER_CLK_DIV1024 ); // set prescaler
outb(TCNT0, 0); // reset TCNT0
outb(OCR0, 0x8C); // set value to output compare register
sbi(TIMSK, OCIE0); // enable output compare match interrupt
// enable interrupts
//sei();
}
