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CommandStation-EX/ATMEGA4809/Timer.h
Asbelos 74c22c83fc FlasString and Timers for Uno Wifi
ALL these changes should be portable back to master
2020-12-09 11:57:38 +00:00

132 lines
3.1 KiB
C++

#ifndef ATMEGA4809Timer_h
#define ATMEGA4809imer_h
#include "../VirtualTimer.h"
#include <Arduino.h>
// We only define behavior for timer 0 (TCA0), because TCB0 is very limited in functionality.
class Timer : public VirtualTimer {
private:
int pwmPeriod;
unsigned long timer_resolution;
unsigned char clockSelectBits;
int timer_num;
unsigned long lastMicroseconds;
public:
void (*isrCallback)();
Timer(int timer_num) {
switch (timer_num)
{
case 0:
timer_resolution = 65536;
break;
}
this->timer_num = timer_num;
lastMicroseconds = 0;
}
void initialize() {
switch (timer_num)
{
case 0:
break;
}
}
void setPeriod(unsigned long microseconds) {
if(microseconds == lastMicroseconds)
return;
lastMicroseconds = microseconds;
const unsigned long cycles = (F_CPU / 1000000) * microseconds;
switch(timer_num) {
case 0:
if (cycles < timer_resolution) {
clockSelectBits = 0x0;
pwmPeriod = cycles;
} else
if (cycles < timer_resolution * 2) {
clockSelectBits = 0x1;
pwmPeriod = cycles / 8;
} else
if (cycles < timer_resolution * 4) {
clockSelectBits = 0x2;
pwmPeriod = cycles / 32;
} else
if (cycles < timer_resolution * 8) {
clockSelectBits = 0x3;
pwmPeriod = cycles / 64;
} else
if (cycles < timer_resolution * 64) {
clockSelectBits = 0x5;
pwmPeriod = cycles / 128;
} else
if (cycles < timer_resolution * 256) {
clockSelectBits = 0x6;
pwmPeriod = cycles / 256;
} else
if (cycles < timer_resolution * 1024) {
clockSelectBits = 0x7;
pwmPeriod = cycles / 1024;
} else {
clockSelectBits = 0x7;
pwmPeriod = timer_resolution - 1;
}
break;
}
switch (timer_num)
{
case 0:
TCA0.SINGLE.PER = pwmPeriod;
TCA0.SINGLE.CTRLA = clockSelectBits << 1;
break;
}
}
void start() {
switch (timer_num)
{
case 0:
bitSet(TCA0.SINGLE.CTRLA, 0);
break;
}
}
void stop() {
switch (timer_num)
{
case 0:
bitClear(TCA0.SINGLE.CTRLA, 0);
break;
}
}
void attachInterrupt(void (*isr)()) {
isrCallback = isr;
switch (timer_num)
{
case 0:
TCA0.SINGLE.INTCTRL = 0x1;
break;
}
}
void detachInterrupt() {
switch (timer_num)
{
case 0:
TCA0.SINGLE.INTCTRL = 0x0;
break;
}
}
};
extern Timer TimerA;
#endif