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Diffstat (limited to 'vga-more/src/TimerHelpers.h')
| -rw-r--r-- | vga-more/src/TimerHelpers.h | 209 |
1 files changed, 209 insertions, 0 deletions
diff --git a/vga-more/src/TimerHelpers.h b/vga-more/src/TimerHelpers.h new file mode 100644 index 0000000..d436987 --- /dev/null +++ b/vga-more/src/TimerHelpers.h @@ -0,0 +1,209 @@ +/* + Timer Helpers library. + +Devised and written by Nick Gammon. +Date: 21 March 2012 +Version: 1.0 + +Licence: Released for public use. + +See: http://www.gammon.com.au/forum/?id=11504 + + Example: + + // set up Timer 1 + TCNT1 = 0; // reset counter + OCR1A = 999; // compare A register value (1000 * clock speed) + + // Mode 4: CTC, top = OCR1A + Timer1::setMode (4, Timer1::PRESCALE_1, Timer1::CLEAR_A_ON_COMPARE); + + TIFR1 |= _BV (OCF1A); // clear interrupt flag + TIMSK1 = _BV (OCIE1A); // interrupt on Compare A Match + +*/ + +#ifndef _TimerHelpers_h +#define _TimerHelpers_h + +#if defined(ARDUINO) && ARDUINO >= 100 + #include "Arduino.h" +#else + #include "WProgram.h" +#endif + +/* --------------------------------------------------------------- + Timer 0 setup + --------------------------------------------------------------- */ + +namespace Timer0 +{ + // TCCR0A, TCCR0B + const byte Modes [8] [2] = + { + + { 0, 0 }, // 0: Normal, top = 0xFF + { _BV (WGM00), 0 }, // 1: PWM, Phase-correct, top = 0xFF + { _BV (WGM01), 0 }, // 2: CTC, top = OCR0A + { _BV (WGM00) | _BV (WGM01), 0 }, // 3: Fast PWM, top = 0xFF + { 0, _BV (WGM02) }, // 4: Reserved + { _BV (WGM00), _BV (WGM02) }, // 5: PWM, Phase-correct, top = OCR0A + { _BV (WGM01), _BV (WGM02) }, // 6: Reserved + { _BV (WGM00) | _BV (WGM01), _BV (WGM02) }, // 7: Fast PWM, top = OCR0A + + }; // end of Timer0::Modes + + // Activation + // Note: T0 is pin 6, Arduino port: D4 + enum { NO_CLOCK, PRESCALE_1, PRESCALE_8, PRESCALE_64, PRESCALE_256, PRESCALE_1024, T0_FALLING, T0_RISING }; + + // what ports to toggle on timer fire + enum { NO_PORT = 0, + + // pin 12, Arduino port: D6 + TOGGLE_A_ON_COMPARE = _BV (COM0A0), + CLEAR_A_ON_COMPARE = _BV (COM0A1), + SET_A_ON_COMPARE = _BV (COM0A0) | _BV (COM0A1), + + // pin 11, Arduino port: D5 + TOGGLE_B_ON_COMPARE = _BV (COM0B0), + CLEAR_B_ON_COMPARE = _BV (COM0B1), + SET_B_ON_COMPARE = _BV (COM0B0) | _BV (COM0B1), + }; + + + // choose a timer mode, set which clock speed, and which port to toggle + void setMode (const byte mode, const byte clock, const byte port) + { + if (mode < 0 || mode > 7) // sanity check + return; + + // reset existing flags + TCCR0A = 0; + TCCR0B = 0; + + TCCR0A |= (Modes [mode] [0]) | port; + TCCR0B |= (Modes [mode] [1]) | clock; + } // end of Timer0::setMode + +} // end of namespace Timer0 + +/* --------------------------------------------------------------- + Timer 1 setup + --------------------------------------------------------------- */ + +namespace Timer1 +{ + // TCCR1A, TCCR1B + const byte Modes [16] [2] = + { + + { 0, 0 }, // 0: Normal, top = 0xFFFF + { _BV (WGM10), 0 }, // 1: PWM, Phase-correct, 8 bit, top = 0xFF + { _BV (WGM11), 0 }, // 2: PWM, Phase-correct, 9 bit, top = 0x1FF + { _BV (WGM10) | _BV (WGM11), 0 }, // 3: PWM, Phase-correct, 10 bit, top = 0x3FF + { 0, _BV (WGM12) }, // 4: CTC, top = OCR1A + { _BV (WGM10), _BV (WGM12) }, // 5: Fast PWM, 8 bit, top = 0xFF + { _BV (WGM11), _BV (WGM12) }, // 6: Fast PWM, 9 bit, top = 0x1FF + { _BV (WGM10) | _BV (WGM11), _BV (WGM12) }, // 7: Fast PWM, 10 bit, top = 0x3FF + { 0, _BV (WGM13) }, // 8: PWM, phase and frequency correct, top = ICR1 + { _BV (WGM10), _BV (WGM13) }, // 9: PWM, phase and frequency correct, top = OCR1A + { _BV (WGM11), _BV (WGM13) }, // 10: PWM, phase correct, top = ICR1A + { _BV (WGM10) | _BV (WGM11), _BV (WGM13) }, // 11: PWM, phase correct, top = OCR1A + { 0, _BV (WGM12) | _BV (WGM13) }, // 12: CTC, top = ICR1 + { _BV (WGM10), _BV (WGM12) | _BV (WGM13) }, // 13: reserved + { _BV (WGM11), _BV (WGM12) | _BV (WGM13) }, // 14: Fast PWM, TOP = ICR1 + { _BV (WGM10) | _BV (WGM11), _BV (WGM12) | _BV (WGM13) }, // 15: Fast PWM, TOP = OCR1A + + }; // end of Timer1::Modes + + // Activation + // Note: T1 is pin 11, Arduino port: D5 + enum { NO_CLOCK, PRESCALE_1, PRESCALE_8, PRESCALE_64, PRESCALE_256, PRESCALE_1024, T1_FALLING, T1_RISING }; + + // what ports to toggle on timer fire + enum { NO_PORT = 0, + + // pin 15, Arduino port: D9 + TOGGLE_A_ON_COMPARE = _BV (COM1A0), + CLEAR_A_ON_COMPARE = _BV (COM1A1), + SET_A_ON_COMPARE = _BV (COM1A0) | _BV (COM1A1), + + // pin 16, Arduino port: D10 + TOGGLE_B_ON_COMPARE = _BV (COM1B0), + CLEAR_B_ON_COMPARE = _BV (COM1B1), + SET_B_ON_COMPARE = _BV (COM1B0) | _BV (COM1B1), + }; + + // choose a timer mode, set which clock speed, and which port to toggle + void setMode (const byte mode, const byte clock, const byte port) + { + if (mode < 0 || mode > 15) // sanity check + return; + + // reset existing flags + TCCR1A = 0; + TCCR1B = 0; + + TCCR1A |= (Modes [mode] [0]) | port; + TCCR1B |= (Modes [mode] [1]) | clock; + } // end of Timer1::setMode + +} // end of namespace Timer1 + +/* --------------------------------------------------------------- + Timer 2 setup + --------------------------------------------------------------- */ + +namespace Timer2 +{ + // TCCR2A, TCCR2B + const byte Modes [8] [2] = + { + + { 0, 0 }, // 0: Normal, top = 0xFF + { _BV (WGM20), 0 }, // 1: PWM, Phase-correct, top = 0xFF + { _BV (WGM21), 0 }, // 2: CTC, top = OCR2A + { _BV (WGM20) | _BV (WGM21), 0 }, // 3: Fast PWM, top = 0xFF + { 0, _BV (WGM22) }, // 4: Reserved + { _BV (WGM20), _BV (WGM22) }, // 5: PWM, Phase-correct, top = OCR2A + { _BV (WGM21), _BV (WGM22) }, // 6: Reserved + { _BV (WGM20) | _BV (WGM21), _BV (WGM22) }, // 7: Fast PWM, top = OCR2A + + }; // end of Timer2::Modes + + // Activation + enum { NO_CLOCK, PRESCALE_1, PRESCALE_8, PRESCALE_32, PRESCALE_64, PRESCALE_128, PRESCALE_256, PRESCALE_1024 }; + + // what ports to toggle on timer fire + enum { NO_PORT = 0, + + // pin 17, Arduino port: D11 + TOGGLE_A_ON_COMPARE = _BV (COM2A0), + CLEAR_A_ON_COMPARE = _BV (COM2A1), + SET_A_ON_COMPARE = _BV (COM2A0) | _BV (COM2A1), + + // pin 5, Arduino port: D3 + TOGGLE_B_ON_COMPARE = _BV (COM2B0), + CLEAR_B_ON_COMPARE = _BV (COM2B1), + SET_B_ON_COMPARE = _BV (COM2B0) | _BV (COM2B1), + }; + + + // choose a timer mode, set which clock speed, and which port to toggle + void setMode (const byte mode, const byte clock, const byte port) + { + if (mode < 0 || mode > 7) // sanity check + return; + + // reset existing flags + TCCR2A = 0; + TCCR2B = 0; + + TCCR2A |= (Modes [mode] [0]) | port; + TCCR2B |= (Modes [mode] [1]) | clock; + } // end of Timer2::setMode + +} // end of namespace Timer2 + +#endif |