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Fix PIT timer period and added functions for getting the current time in microseconds

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This commit is contained in:
Kristian Sloth Lauszus
2018-06-22 17:39:22 +02:00
parent b1cbeefa28
commit d449123fab
2 changed files with 42 additions and 7 deletions
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45
right/src/timer.c
View File

@@ -1,12 +1,15 @@
#include "fsl_pit.h" #include "fsl_pit.h"
#include "timer.h" #include "timer.h"
#include "peripherals/test_led.h"
static volatile uint32_t CurrentTime; static volatile uint32_t CurrentTime;
static uint32_t timerClockFrequency;
void PIT_TIMER_HANDLER(void) void PIT_TIMER_HANDLER(void)
{ {
CurrentTime++; CurrentTime++;
PIT_ClearStatusFlags(PIT, PIT_TIMER_CHANNEL, PIT_TFLG_TIF_MASK); //TEST_LED_TOGGLE();
PIT_ClearStatusFlags(PIT, PIT_TIMER_CHANNEL, kPIT_TimerFlag);
} }
void Timer_Init(void) void Timer_Init(void)
@@ -15,9 +18,8 @@ void Timer_Init(void)
PIT_GetDefaultConfig(&pitConfig); PIT_GetDefaultConfig(&pitConfig);
PIT_Init(PIT, &pitConfig); PIT_Init(PIT, &pitConfig);
// TODO: Why the interval needs to be multiplied by two to arrive to the correct timing? timerClockFrequency = PIT_SOURCE_CLOCK;
// Figure it out and clean this up. PIT_SetTimerPeriod(PIT, PIT_TIMER_CHANNEL, MSEC_TO_COUNT(TIMER_INTERVAL_MSEC, timerClockFrequency));
PIT_SetTimerPeriod(PIT, PIT_TIMER_CHANNEL, MSEC_TO_COUNT(TIMER_INTERVAL_MSEC*2, PIT_SOURCE_CLOCK));
PIT_EnableInterrupts(PIT, PIT_TIMER_CHANNEL, kPIT_TimerInterruptEnable); PIT_EnableInterrupts(PIT, PIT_TIMER_CHANNEL, kPIT_TimerInterruptEnable);
EnableIRQ(PIT_TIMER_IRQ_ID); EnableIRQ(PIT_TIMER_IRQ_ID);
@@ -28,20 +30,49 @@ uint32_t Timer_GetCurrentTime() {
return CurrentTime; return CurrentTime;
} }
uint32_t Timer_GetCurrentTimeMicros() {
uint32_t primask, count, ms;
primask = DisableGlobalIRQ(); // Make sure the read is atomic
count = PIT_GetCurrentTimerCount(PIT, PIT_TIMER_CHANNEL); // Read the current timer count
ms = CurrentTime; // Read the overflow counter
EnableGlobalIRQ(primask); // Enable interrupts again if they where enabled before - this should make it interrupt safe
uint32_t us = COUNT_TO_USEC(count, timerClockFrequency);
return ms * 1000U * TIMER_INTERVAL_MSEC + us;
}
void Timer_SetCurrentTime(uint32_t *time) void Timer_SetCurrentTime(uint32_t *time)
{ {
*time = CurrentTime; *time = Timer_GetCurrentTime();
}
void Timer_SetCurrentTimeMicros(uint32_t *time)
{
*time = Timer_GetCurrentTimeMicros();
} }
uint32_t Timer_GetElapsedTime(uint32_t *time) uint32_t Timer_GetElapsedTime(uint32_t *time)
{ {
uint32_t elapsedTime = CurrentTime - *time; uint32_t elapsedTime = Timer_GetCurrentTime() - *time;
return elapsedTime;
}
uint32_t Timer_GetElapsedTimeMicros(uint32_t *time)
{
uint32_t elapsedTime = Timer_GetCurrentTimeMicros() - *time;
return elapsedTime; return elapsedTime;
} }
uint32_t Timer_GetElapsedTimeAndSetCurrent(uint32_t *time) uint32_t Timer_GetElapsedTimeAndSetCurrent(uint32_t *time)
{ {
uint32_t elapsedTime = Timer_GetElapsedTime(time); uint32_t elapsedTime = Timer_GetElapsedTime(time);
*time = CurrentTime; *time = Timer_GetCurrentTime();
return elapsedTime;
}
uint32_t Timer_GetElapsedTimeAndSetCurrentMicros(uint32_t *time)
{
uint32_t elapsedTime = Timer_GetElapsedTimeMicros(time);
*time = Timer_GetCurrentTimeMicros();
return elapsedTime; return elapsedTime;
} }

4
right/src/timer.h
View File

@@ -13,8 +13,12 @@
void Timer_Init(void); void Timer_Init(void);
uint32_t Timer_GetCurrentTime(); uint32_t Timer_GetCurrentTime();
uint32_t Timer_GetCurrentTimeMicros();
void Timer_SetCurrentTime(uint32_t *time); void Timer_SetCurrentTime(uint32_t *time);
void Timer_SetCurrentTimeMicros(uint32_t *time);
uint32_t Timer_GetElapsedTime(uint32_t *time); uint32_t Timer_GetElapsedTime(uint32_t *time);
uint32_t Timer_GetElapsedTimeMicros(uint32_t *time);
uint32_t Timer_GetElapsedTimeAndSetCurrent(uint32_t *time); uint32_t Timer_GetElapsedTimeAndSetCurrent(uint32_t *time);
uint32_t Timer_GetElapsedTimeAndSetCurrentMicros(uint32_t *time);
#endif #endif