Timer

Hardware timers. More...

Files
file	InputCapture.h
	Software driver functions for input capture.
file	Timer.h
	Initialize Periodic interrupt timers.

Macros
#define	INPUTCAPTUREUSELFCLK   2
	use INPUTCAPTUREUSELFCLK to select 32768 Hz LFCLK
#define	INPUTCAPTUREUSEMFCLK   4
	use INPUTCAPTUREUSEMFCLK to select MFCLK (not tested)
#define	INPUTCAPTUREUSEBUSCLK   8
	use INPUTCAPTUREUSEBUSCLK to select BUSCLK

Functions
void	InputCapture_Init (uint32_t timerClkSrc, uint32_t timerClkPrescale, uint32_t priority)
	Initialize input capture. More...
void	InputCapture_InitDual (uint32_t timerClkSrc, uint32_t timerClkPrescale, uint32_t priority)
void	TimerG0_IntArm (uint16_t period, uint32_t prescale, uint32_t priority)
	Initialize Timer G0 interrupt. More...
void	TimerG8_IntArm (uint16_t period, uint32_t prescale, uint32_t priority)
	Initialize Timer G8 interrupt. More...
void	TimerA0_IntArm (uint16_t period, uint32_t prescale, uint32_t priority)
	Initialize Timer A0 interrupt. More...
void	TimerA1_IntArm (uint16_t period, uint32_t prescale, uint32_t priority)
	Initialize Timer A1 interrupt. More...
void	TimerG7_IntArm (uint16_t period, uint32_t prescale, uint32_t priority)
	Initialize Timer G7 interrupt. More...
void	TimerG6_IntArm (uint16_t period, uint32_t prescale, uint32_t priority)
	Initialize Timer G6 interrupt. More...
void	TimerG12_IntArm (uint32_t period, uint32_t priority)
	Initialize Timer G12 interrupt. More...
void	TimerG12_Init (void)
	Initialize Timer G12. More...

Detailed Description

Hardware timers.

Input capture pins

Pin	Timer	Description
PA12	TIMG0	interrupts on rising edge of PA12

Function Documentation

InputCapture_Init()

void InputCapture_Init	(	uint32_t	timerClkSrc,
		uint32_t	timerClkPrescale,
		uint32_t	priority
	)

Initialize input capture.

Arm interrupts on rising edge of PA12
Let P be the period of the selected clock
resolution = P*(timerClkPrescale+1)
precision = 16 bits
range = 65535*resolution (max)
timerClkDivRatio = 1
timerClkFreq = (timerClkSrc / (timerClkDivRatio * (timerClkPrescale + 1)))
resolution = (timerClkDivRatio * (timerClkPrescale + 1)))/timerClkSrc
User defines their own ISR like the following

uint32_t Data[20];
uint32_t Index=0;
uint32_t Time,Last,Period;
uint32_t iidx,count=0;
void TIMG0_IRQHandler(void){
  count++;
  iidx = TIMG0->CPU_INT.IIDX;// this will acknowledge
  if((iidx) == 5){ // 5 means capture CCD0
    Time = TIMG0->COUNTERREGS.CC_01[0]; // time now
    Period  = (Last-Time)&0xFFFF; // elapsed time since last
    Last = Time;
    if(Index < 20){
      Data[Index] = Period;
      Index++;
    }
  }
}

• timerClkSrc
  
  • 2 for 32768 Hz LFCLK
    
  • 4 for MFCLK (not tested)
    
  • 8 for BUSCLK
• For example
  • source=LFCLK, prescale=255, resolution = 7.8125ms
  • source=BUSCLK, prescale=47, resolution = 1us

Parameters

timerClkSrc	could be LFCLK, MFCLK, or BUSCLK
timerClkPrescale	is prescale divide clock by timerClkPrescale+1, 0 to 255
priority	is 0(highest),1,2 or 3(lowest)

Returns

none

Note

Will invoke LaunchPad_Init

TimerA0_IntArm()

void TimerA0_IntArm	(	uint16_t	period,
		uint32_t	prescale,
		uint32_t	priority
	)

Initialize Timer A0 interrupt.

Arm 16-bit periodic interrupts on Timer A0. TimerA0 is on power Domain PD1

• 32MHz bus clock, Timer clock is 32MHz
• 40MHz bus clock, Timer clock is ULPCLK 40MHz
• 80MHz bus clock, Timer clock is ULPCLK 80MHz

frequency = TimerClock/prescale/period

Parameters

period	sets the interrupt 16-bit period
prescale	sets the timer prescale
priority	is 0(highest),1,2 or 3(lowest)

Returns

none

Note

interrupts will be enabled in main after all initialization User defines their own ISR like the following

uint32_t count;
void TIMA0_IRQHandler(void){
  if((TIMA0->CPU_INT.IIDX) == 1){ // this will acknowledge
    GPIOB->DOUTTGL31_0 = GREEN; // toggle PB27
    count++;
  }
}

TimerA1_IntArm()

void TimerA1_IntArm	(	uint16_t	period,
		uint32_t	prescale,
		uint32_t	priority
	)

Initialize Timer A1 interrupt.

Arm 16-bit periodic interrupts on Timer A1. TimerA1 is on power Domain PD1

• 32MHz bus clock, Timer clock is 32MHz
• 40MHz bus clock, Timer clock is ULPCLK 40MHz
• 80MHz bus clock, Timer clock is ULPCLK 80MHz

frequency = TimerClock/prescale/period

Parameters

period	sets the interrupt 16-bit period
prescale	sets the timer prescale
priority	is 0(highest),1,2 or 3(lowest)

Returns

none

Note

interrupts will be enabled in main after all initialization User defines their own ISR like the following

uint32_t count;
void TIMA1_IRQHandler(void){
  if((TIMA1->CPU_INT.IIDX) == 1){ // this will acknowledge
    GPIOB->DOUTTGL31_0 = GREEN; // toggle PB27
    count++;
  }
}

TimerG0_IntArm()

void TimerG0_IntArm	(	uint16_t	period,
		uint32_t	prescale,
		uint32_t	priority
	)

Initialize Timer G0 interrupt.

Arm 16-bit periodic interrupts on Timer G0. TimerG0 is on power Domain PD0

• 32MHz bus clock, Timer clock is 32MHz
• 40MHz bus clock, Timer clock is ULPCLK 20MHz
• 80MHz bus clock, Timer clock is ULPCLK 40MHz

frequency = TimerClock/prescale/period

Parameters

period	sets the interrupt 16-bit period
prescale	sets the timer prescale
priority	is 0(highest),1,2 or 3(lowest)

Returns

none

Note

interrupts will be enabled in main after all initialization User defines their own ISR like the following

uint32_t count;
void TIMG0_IRQHandler(void){
  if((TIMG0->CPU_INT.IIDX) == 1){ // this will acknowledge
    GPIOB->DOUTTGL31_0 = GREEN; // toggle PB27
    count++;
  }
}

TimerG12_Init()

void TimerG12_Init

(

void

)

Initialize Timer G12.

initialize G12 for continuous counting. No prescale
simply read TIMG12->COUNTERREGS.CTR for 32 bit time

• resolution is bus clock, for 80 MHz clock, 12.5ns
• precision is 32 bits,

TimerG12 is on power Domain PD1

• 32MHz bus clock, Timer clock is 32MHz
• 40MHz bus clock, Timer clock is ULPCLK 40MHz
• 80MHz bus clock, Timer clock is ULPCLK 80MHz

Parameters

none

Returns

none

Note

Example use to measure execution time of myfunction

uint32_t elapsed,start,end;
  TimerG12_Init(); // start timer G12 
  start = TIMG12->COUNTERREGS.CTR;
  myfunction();
  end = TIMG12->COUNTERREGS.CTR;
  elapsed = start-end; // 12.5ns resolution

TimerG12_IntArm()

void TimerG12_IntArm	(	uint32_t	period,
		uint32_t	priority
	)

Initialize Timer G12 interrupt.

Arm 32-bit periodic interrupts on Timer G12. No prescale TimerG12 is on power Domain PD1

• 32MHz bus clock, Timer clock is 32MHz
• 40MHz bus clock, Timer clock is ULPCLK 40MHz
• 80MHz bus clock, Timer clock is ULPCLK 80MHz

frequency = TimerClock/period

Parameters

period	32-bit sets the interrupt period
priority	is 0(highest),1,2 or 3(lowest)

Returns

none

Note

interrupts will be enabled in main after all initialization User defines their own ISR like the following

uint32_t count;
void TIMG12_IRQHandler(void){
  if((TIMG12->CPU_INT.IIDX) == 1){ // this will acknowledge
    GPIOB->DOUTTGL31_0 = GREEN; // toggle PB27
    count++;
  }
}

TimerG6_IntArm()

void TimerG6_IntArm	(	uint16_t	period,
		uint32_t	prescale,
		uint32_t	priority
	)

Initialize Timer G6 interrupt.

Arm 16-bit periodic interrupts on Timer G6. TimerG6 is on power Domain PD1

• 32MHz bus clock, Timer clock is 32MHz
• 40MHz bus clock, Timer clock is ULPCLK 40MHz
• 80MHz bus clock, Timer clock is ULPCLK 80MHz

frequency = TimerClock/prescale/period

Parameters

period	sets the interrupt 16-bit period
prescale	sets the timer prescale
priority	is 0(highest),1,2 or 3(lowest)

Returns

none

Note

interrupts will be enabled in main after all initialization User defines their own ISR like the following

uint32_t count;
void TIMG6_IRQHandler(void){
  if((TIMG6->CPU_INT.IIDX) == 1){ // this will acknowledge
    GPIOB->DOUTTGL31_0 = GREEN; // toggle PB27
    count++;
  }
}

TimerG7_IntArm()

void TimerG7_IntArm	(	uint16_t	period,
		uint32_t	prescale,
		uint32_t	priority
	)

Initialize Timer G7 interrupt.

Arm 16-bit periodic interrupts on Timer G7. TimerG7 is on power Domain PD1

• 32MHz bus clock, Timer clock is 32MHz
• 40MHz bus clock, Timer clock is ULPCLK 40MHz
• 80MHz bus clock, Timer clock is ULPCLK 80MHz

frequency = TimerClock/prescale/period

Parameters

period	sets the interrupt 16-bit period
prescale	sets the timer prescale
priority	is 0(highest),1,2 or 3(lowest)

Returns

none

Note

interrupts will be enabled in main after all initialization User defines their own ISR like the following

uint32_t count;
void TIMG7_IRQHandler(void){
  if((TIMG7->CPU_INT.IIDX) == 1){ // this will acknowledge
    GPIOB->DOUTTGL31_0 = GREEN; // toggle PB27
    count++;
  }
}

TimerG8_IntArm()

void TimerG8_IntArm	(	uint16_t	period,
		uint32_t	prescale,
		uint32_t	priority
	)

Initialize Timer G8 interrupt.

Arm 16-bit periodic interrupts on Timer G8. TimerG8 is on power Domain PD0

• 32MHz bus clock, Timer clock is 32MHz
• 40MHz bus clock, Timer clock is ULPCLK 20MHz
• 80MHz bus clock, Timer clock is ULPCLK 40MHz

frequency = TimerClock/prescale/period

Parameters

period	sets the interrupt 16-bit period
prescale	sets the timer prescale
priority	is 0(highest),1,2 or 3(lowest)

Returns

none

Note

interrupts will be enabled in main after all initialization User defines their own ISR like the following

uint32_t count;
void TIMG8_IRQHandler(void){
  if((TIMG8->CPU_INT.IIDX) == 1){ // this will acknowledge
    GPIOB->DOUTTGL31_0 = GREEN; // toggle PB27
    count++;
  }
}