File content as of revision 2:5056ec8c52e8:

/* Timer_LPTMR.cpp
 * Tested with mbed board: FRDM-KL46Z
 * Author: Mark Gottscho
 * mgottscho@ucla.edu
 */

#include "mbed.h"
#include "HardwareTimer.h"
#include "Timer_LPTMR.h"
#include "PreciseTime.h"

//Init class static variable
bool Timer_LPTMR::__initialized_lptmr = false;
uint16_t Timer_LPTMR::__rolloverValue = 0xFFFF;
uint32_t Timer_LPTMR::__count = 0;

Timer_LPTMR::Timer_LPTMR(float tickValue) :
            HardwareTimer(tickValue)
            {
}

Timer_LPTMR::~Timer_LPTMR() {}

void Timer_LPTMR::disableTimer() {
    if (!__valid)
        return;
        
    LPTMR0->CSR = 0; //Reset the LPTMR timer control/status register
    __enabled = false;
}

uint32_t Timer_LPTMR::getTick() {
    if (!__valid)
        return 0;
        
    //Get the raw time
    __disable_irq();
    LPTMR0->CNR = 0; //need to write to the register in order to read it due to buffering
    uint16_t ticks = LPTMR0->CNR;
    uint32_t count = __count;
    __enable_irq();
    
    //Convert to ticks
    return (uint32_t) ((count * __rolloverValue) + ticks);
}


void Timer_LPTMR::__isr_lptmr() {
    LPTMR0->CSR |= LPTMR_CSR_TCF_MASK;  //Write 1 to TCF to clear the LPT timer compare flag
    __set_lptmr(__rolloverValue); //Set timer again
    __count++;
}

void Timer_LPTMR::__set_lptmr(uint16_t count) {
    LPTMR0->CSR = 0; //Reset the timer control/status register
    LPTMR0->CMR = count; //Set the compare register
    LPTMR0->CSR |= LPTMR_CSR_TIE_MASK; //Enable interrupt
   // LPTMR0->CSR |= LPTMR_CSR_TFC_MASK; //Set free-running mode
    LPTMR0->CSR |= LPTMR_CSR_TEN_MASK; //Start the timer
}