Andrew Boyson / clock

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Dependents:   oldheating gps motorhome heating

tick.c@17:927fc1eceb9d, 2018-01-11 (annotated)

Committer:
andrewboyson
Date:
Thu Jan 11 17:39:36 2018 +0000
Revision:
17:927fc1eceb9d
Parent:
tick.cpp@16:933cbe190bb0
Child:
18:207dd1474cd9
Removed dependence on Mbed OS

Who changed what in which revision?

UserRevisionLine numberNew contents of line
andrewboyson 17:927fc1eceb9d 1 #include "peripherals.h"
andrewboyson 14:7ef557918bb1 2 #include "rtc.h"
andrewboyson 14:7ef557918bb1 3 #include "time.h"
andrewboyson 14:7ef557918bb1 4 #include "tick.h"
andrewboyson 17:927fc1eceb9d 5
andrewboyson 17:927fc1eceb9d 6 #define TRUE 1
andrewboyson 17:927fc1eceb9d 7 #define FALSE 0
andrewboyson 0:33686e88f09a 8
andrewboyson 0:33686e88f09a 9 #define ONE_BILLION 1000000000
andrewboyson 0:33686e88f09a 10
andrewboyson 16:933cbe190bb0 11 static volatile int64_t nsTickCount;
andrewboyson 16:933cbe190bb0 12 static volatile int64_t nsFreqCount;
andrewboyson 16:933cbe190bb0 13 static volatile int64_t nsTimeCount;
andrewboyson 16:933cbe190bb0 14
andrewboyson 17:927fc1eceb9d 15 static int nsCountIsSet = FALSE;
andrewboyson 17:927fc1eceb9d 16 int TickIsSet() { return nsCountIsSet; }
andrewboyson 5:a3e37ce4975d 17 void TickSet(int64_t extClock)
andrewboyson 5:a3e37ce4975d 18 {
andrewboyson 5:a3e37ce4975d 19 nsTickCount = 0;
andrewboyson 5:a3e37ce4975d 20 nsFreqCount = 0;
andrewboyson 5:a3e37ce4975d 21 nsTimeCount = extClock;
andrewboyson 5:a3e37ce4975d 22 LPC_TIM1->TCR = 2; // 21.6.2 Timer Control Register - Reset TC and PC.
andrewboyson 5:a3e37ce4975d 23 LPC_TIM1->TCR = 1; // 21.6.2 Timer Control Register - Enable TC and PC.
andrewboyson 17:927fc1eceb9d 24 nsCountIsSet = TRUE;
andrewboyson 5:a3e37ce4975d 25 }
andrewboyson 0:33686e88f09a 26
andrewboyson 16:933cbe190bb0 27 static volatile int32_t slew = 0; //ns - up to +/- 2.147s of slew
andrewboyson 5:a3e37ce4975d 28 int32_t TickGetSlew() { return slew; }
andrewboyson 5:a3e37ce4975d 29 void TickSetSlew(int32_t value) { slew = value; }
andrewboyson 5:a3e37ce4975d 30
andrewboyson 16:933cbe190bb0 31 static volatile int32_t ppb = 0;
andrewboyson 5:a3e37ce4975d 32 int32_t TickGetPpb () { return ppb; }
andrewboyson 5:a3e37ce4975d 33 void TickSetPpb (int32_t value) { ppb = value; LPC_RTC->GPREG0 = ppb; }
andrewboyson 5:a3e37ce4975d 34 void TickAddPpb (int32_t value) { ppb += value; LPC_RTC->GPREG0 = ppb; }
andrewboyson 0:33686e88f09a 35
andrewboyson 0:33686e88f09a 36 #define CLOCK_TIC 0
andrewboyson 0:33686e88f09a 37 #define CLOCK_INT 1
andrewboyson 0:33686e88f09a 38 #define CLOCK_ABS 2
andrewboyson 0:33686e88f09a 39
andrewboyson 17:927fc1eceb9d 40 __irq void TickHandler(void)
andrewboyson 9:cd30749dfa3d 41 {//Checked the number of counts and this routine takes 46 counts or about 0.5us
andrewboyson 9:cd30749dfa3d 42
andrewboyson 0:33686e88f09a 43 //Reset the timer interrupt
andrewboyson 0:33686e88f09a 44 LPC_TIM1->IR |= 1;
andrewboyson 0:33686e88f09a 45
andrewboyson 0:33686e88f09a 46 //reset the tick timer
andrewboyson 0:33686e88f09a 47 LPC_TIM1->TCR = 2; // 21.6.2 Timer Control Register - Reset TC and PC.
andrewboyson 0:33686e88f09a 48 LPC_TIM1->TCR = 1; // 21.6.2 Timer Control Register - Enable TC and PC
andrewboyson 0:33686e88f09a 49
andrewboyson 0:33686e88f09a 50 //Calculate the new counts
andrewboyson 0:33686e88f09a 51 nsTickCount += ONE_BILLION;
andrewboyson 5:a3e37ce4975d 52 nsFreqCount += ppb;
andrewboyson 5:a3e37ce4975d 53 nsTimeCount += slew;
andrewboyson 0:33686e88f09a 54
andrewboyson 0:33686e88f09a 55 //Feedback the amount slewed
andrewboyson 5:a3e37ce4975d 56 slew = 0;
andrewboyson 0:33686e88f09a 57 }
andrewboyson 0:33686e88f09a 58 static volatile int64_t nsTickSnapshot;
andrewboyson 0:33686e88f09a 59 static volatile int64_t nsFreqSnapshot;
andrewboyson 0:33686e88f09a 60 static volatile int64_t nsTimeSnapshot;
andrewboyson 0:33686e88f09a 61 static volatile int32_t timerSnapshot;
andrewboyson 0:33686e88f09a 62
andrewboyson 0:33686e88f09a 63 void TickSaveSnapshotI()
andrewboyson 0:33686e88f09a 64 {
andrewboyson 0:33686e88f09a 65 timerSnapshot = LPC_TIM1->TC;
andrewboyson 0:33686e88f09a 66 nsTickSnapshot = nsTickCount;
andrewboyson 0:33686e88f09a 67 nsFreqSnapshot = nsFreqCount;
andrewboyson 0:33686e88f09a 68 nsTimeSnapshot = nsTimeCount;
andrewboyson 0:33686e88f09a 69 }
andrewboyson 14:7ef557918bb1 70 static void makeTimesFromCounts(int32_t timerCount, int64_t tickNs, int64_t freqNs, int64_t timeNs, int64_t* pNsInt, int64_t* pNsAbs)
andrewboyson 16:933cbe190bb0 71 {
andrewboyson 16:933cbe190bb0 72 int64_t fraction = timerCount;
andrewboyson 16:933cbe190bb0 73 fraction <<= 32;
andrewboyson 16:933cbe190bb0 74 fraction /= TICK_COUNT_PER_SECOND;
andrewboyson 16:933cbe190bb0 75
andrewboyson 0:33686e88f09a 76 int64_t nsFraction;
andrewboyson 0:33686e88f09a 77
andrewboyson 14:7ef557918bb1 78 int64_t nsBase = tickNs;
andrewboyson 0:33686e88f09a 79 int64_t nsPerTick = ONE_BILLION;
andrewboyson 16:933cbe190bb0 80
andrewboyson 14:7ef557918bb1 81 nsBase += freqNs;
andrewboyson 5:a3e37ce4975d 82 nsPerTick += ppb;
andrewboyson 0:33686e88f09a 83 nsFraction = (nsPerTick * fraction) >> 32;
andrewboyson 0:33686e88f09a 84 *pNsInt = nsBase + nsFraction;
andrewboyson 0:33686e88f09a 85
andrewboyson 14:7ef557918bb1 86 nsBase += timeNs;
andrewboyson 5:a3e37ce4975d 87 nsPerTick += slew;
andrewboyson 0:33686e88f09a 88 nsFraction = (nsPerTick * fraction) >> 32;
andrewboyson 0:33686e88f09a 89 *pNsAbs = nsBase + nsFraction;
andrewboyson 0:33686e88f09a 90 }
andrewboyson 14:7ef557918bb1 91 void TickRetrieveSnapshot(int64_t* pNsInt, int64_t* pNsAbs)
andrewboyson 14:7ef557918bb1 92 {
andrewboyson 14:7ef557918bb1 93 makeTimesFromCounts(timerSnapshot, nsTickSnapshot, nsFreqSnapshot, nsTimeSnapshot, pNsInt, pNsAbs);
andrewboyson 14:7ef557918bb1 94 }
andrewboyson 6:d8a6235486b7 95 void TickGetTimes(int64_t* pNsInt, int64_t* pNsAbs)
andrewboyson 0:33686e88f09a 96 {
andrewboyson 14:7ef557918bb1 97 int32_t timerCount;
andrewboyson 14:7ef557918bb1 98 int64_t tickNs;
andrewboyson 14:7ef557918bb1 99 int64_t freqNs;
andrewboyson 14:7ef557918bb1 100 int64_t timeNs;
andrewboyson 14:7ef557918bb1 101
andrewboyson 0:33686e88f09a 102 __disable_irq();
andrewboyson 14:7ef557918bb1 103 timerCount = LPC_TIM1->TC;
andrewboyson 14:7ef557918bb1 104 tickNs = nsTickCount;
andrewboyson 14:7ef557918bb1 105 freqNs = nsFreqCount;
andrewboyson 14:7ef557918bb1 106 timeNs = nsTimeCount;
andrewboyson 0:33686e88f09a 107 __enable_irq();
andrewboyson 6:d8a6235486b7 108
andrewboyson 14:7ef557918bb1 109 makeTimesFromCounts(timerCount, tickNs, freqNs, timeNs, pNsInt, pNsAbs);
andrewboyson 0:33686e88f09a 110 }
andrewboyson 0:33686e88f09a 111
andrewboyson 17:927fc1eceb9d 112 void TickInit(void)
andrewboyson 0:33686e88f09a 113 {
andrewboyson 0:33686e88f09a 114 nsTickCount = 0;
andrewboyson 0:33686e88f09a 115 nsFreqCount = 0;
andrewboyson 0:33686e88f09a 116 nsTimeCount = 0;
andrewboyson 0:33686e88f09a 117
andrewboyson 5:a3e37ce4975d 118 ppb = LPC_RTC->GPREG0; //This is saved each time Tickppb is updated
andrewboyson 5:a3e37ce4975d 119 slew = 0;
andrewboyson 17:927fc1eceb9d 120 nsCountIsSet = FALSE;
andrewboyson 0:33686e88f09a 121
andrewboyson 14:7ef557918bb1 122 LPC_SC->PCLKSEL0 &= ~0x20; // 4.7.3 Peripheral Clock Selection - PCLK_peripheral PCLK_TIMER1 01xxxx = CCLK - reset bit 5
andrewboyson 14:7ef557918bb1 123 LPC_SC->PCLKSEL0 |= 0x10; // set bit 4
andrewboyson 14:7ef557918bb1 124 LPC_SC->PCONP |= 4; // 4.8.9 Power Control for Peripherals register - Timer1 Power On
andrewboyson 14:7ef557918bb1 125 LPC_TIM1->TCR = 2; // 21.6.2 Timer Control Register - Reset TC and PC.
andrewboyson 14:7ef557918bb1 126 LPC_TIM1->CTCR = 0; // 21.6.3 Count Control Register - Timer mode
andrewboyson 14:7ef557918bb1 127 LPC_TIM1->PR = 0; // 21.6.5 Prescale register - Don't prescale 96MHz clock (divide by PR+1).
andrewboyson 14:7ef557918bb1 128 LPC_TIM1->MR0 = TICK_COUNT_PER_SECOND; // 21.6.7 Match Register 0 - Match count
andrewboyson 14:7ef557918bb1 129 LPC_TIM1->MCR = 1; // 21.6.8 Match Control Register - interrupt on match
andrewboyson 14:7ef557918bb1 130 LPC_TIM1->TCR = 1; // 21.6.2 Timer Control Register - Enable TC and PC
andrewboyson 0:33686e88f09a 131
andrewboyson 17:927fc1eceb9d 132 NVIC->ISER[0] |= 0x04; // 6.5.1 bit2 == Interrupt set enable for timer 1.
andrewboyson 0:33686e88f09a 133 }
andrewboyson 14:7ef557918bb1 134 int32_t TickElapsed(int32_t* pLastTime)
andrewboyson 14:7ef557918bb1 135 {
andrewboyson 14:7ef557918bb1 136 int32_t thisTime = LPC_TIM1->TC;
andrewboyson 14:7ef557918bb1 137
andrewboyson 14:7ef557918bb1 138 if (thisTime < *pLastTime) *pLastTime -= TICK_COUNT_PER_SECOND; //lastCount could be 96 000 002 and thisTime could be 00 000 100 which should give 98
andrewboyson 14:7ef557918bb1 139 int32_t elapsed = thisTime - *pLastTime;
andrewboyson 14:7ef557918bb1 140
andrewboyson 14:7ef557918bb1 141 *pLastTime = thisTime;
andrewboyson 14:7ef557918bb1 142 return elapsed;
andrewboyson 14:7ef557918bb1 143 }
andrewboyson 17:927fc1eceb9d 144 int Ticked(int32_t* pLastTime)
andrewboyson 14:7ef557918bb1 145 {
andrewboyson 14:7ef557918bb1 146 int thisTime = LPC_TIM1->TC;
andrewboyson 14:7ef557918bb1 147
andrewboyson 17:927fc1eceb9d 148 int ticked = thisTime < *pLastTime;
andrewboyson 14:7ef557918bb1 149
andrewboyson 14:7ef557918bb1 150 *pLastTime = thisTime;
andrewboyson 14:7ef557918bb1 151 return ticked;
andrewboyson 14:7ef557918bb1 152 }