Revision 20:62e0760cae13, committed 2018-01-18

Comitter:

andrewboyson

Date:

Thu Jan 18 18:07:30 2018 +0000

Parent:

19:e537bacd1478

Child:

21:48fe75bcde84

Commit message:

Corrected an error in the Tick Set routine

Changed in this revision

--- a/clock.c	Wed Jan 17 20:42:14 2018 +0000
+++ b/clock.c	Thu Jan 18 18:07:30 2018 +0000
@@ -79,8 +79,6 @@
     TickInit();
 }
 
-int ClockTicked = 0; //Set to true for one scan each time the second changes
-
 uint32_t ClockScanAverage = 0;
 uint32_t ClockScanMinimum = 10000;
 uint32_t ClockScanMaximum = 0;
@@ -127,16 +125,11 @@
          
     //Record the time the clock started
     if (SyncedTime && SyncedRate) refNs = nowNs;
-
-    //Set a one shot memory for having had a tick
-    static time_t lastT = 0;
-    ClockTicked = lastT > 0 && lastT != nowT;
-    lastT = nowT;
         
     if (TickIsSet())
     {
         //Save the time to the RTC on the second
-        if (ClockTicked)
+        if (TickTicked)
         {
             struct tm tm;
             ClockTmUtc(&tm);

--- a/clock.h	Wed Jan 17 20:42:14 2018 +0000
+++ b/clock.h	Thu Jan 18 18:07:30 2018 +0000
@@ -22,7 +22,6 @@
 extern void    ClockTmLocal(struct tm* ptm);
 extern void    ClockTmUtc  (struct tm* ptm);
 
-extern bool     ClockTicked;
 extern uint32_t ClockScanAverage;
 extern uint32_t ClockScanMinimum;
 extern uint32_t ClockScanMaximum;

--- a/counter.c	Wed Jan 17 20:42:14 2018 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,73 +0,0 @@
-#include <stdint.h>
-
-#include "peripherals.h"
-
-
-#define SECONDS_PER_TICK 45;
-#define TICK_COUNT_PER_SECOND 96000000
-
-
-static int32_t ppb = 0;
-static int32_t ns = 0;
-static int64_t freqCount = 0; //1 second = 96,000,000 counts
-static int64_t slewCount = 0; //1 ns = 96 counts
-
-int64_t CounterGetI() //Call this from an interrupt or if interrupts are already disabled
-{
-    static uint32_t lastCount = 0;
-    static uint32_t ticks = 0;
-    
-    uint32_t thisCount = LPC_TIM1->TC;
-    if (thisCount < lastCount)
-    {
-        ++ticks;
-        freqCount += ppb * SECONDS_PER_TICK;
-        slewCount +=  ns * SECONDS_PER_TICK;
-        ns = 0;
-    }
-        
-    lastCount = thisCount;
-
-    return ((int64_t)ticks << 32) | thisCount;
-}
-int64_t CounterGet() //Call this from the main thread
-{
-    __disable_irq();
-        int64_t count = CounterGetI();
-    __enable_irq();
-
-    return count;
-}
-
-static volatile int64_t nsTickCount;
-static volatile int64_t nsFreqCount;
-static volatile int64_t nsTimeCount;
-
-uint32_t CounterGetFractionOfSecond()
-{
-    static uint32_t lastCall = 0;
-    uint32_t sinceLastCall = LPC_TIM1->TC - lastCall;
-    if (sinceLastCall > TICK_COUNT_PER_SECOND)
-    {
-             lastCall += TICK_COUNT_PER_SECOND;
-        sinceLastCall -= TICK_COUNT_PER_SECOND;
-    }
-    return sinceLastCall;
-}
-
-void CounterInit(void)
-{    
-    LPC_SC->PCONP    |=     4; //  4.8.9 Power Control for Peripherals register - Timer1 Power On
-    LPC_TIM1->TCR     =     2; // 21.6.2 Timer Control Register - Reset TC and PC.
-    LPC_TIM1->CTCR    =     0; // 21.6.3 Count Control Register - Timer mode
-    LPC_TIM1->PR      =     0; // 21.6.5 Prescale register      - Don't prescale 96MHz clock (divide by PR+1).
-    LPC_TIM1->MCR     =     0; // 21.6.8 Match Control Register - interrupt on match
-    LPC_TIM1->TCR     =     1; // 21.6.2 Timer Control Register - Enable TC and PC
-}
-uint32_t CounterSinceLastCall(uint32_t* pLastTime)
-{
-    uint32_t thisTime = LPC_TIM1->TC;
-    uint32_t elapsed = thisTime - *pLastTime; //unsigned subtraction
-    *pLastTime = thisTime;
-    return elapsed;
-}

--- a/counter.h	Wed Jan 17 20:42:14 2018 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,7 +0,0 @@
-#include <stdint.h>
-
-extern int64_t CounterGetI(void);
-extern int64_t CounterGet(void);
-extern void    CounterInit(void);
-extern int32_t CounterSinceLastCall(int32_t* pLastTime);
-

--- a/tick.c	Wed Jan 17 20:42:14 2018 +0000
+++ b/tick.c	Thu Jan 18 18:07:30 2018 +0000
@@ -13,16 +13,8 @@
 static volatile int64_t nsTickCount;
 static volatile int64_t nsFreqCount;
 static volatile int64_t nsTimeCount;
-
 static bool nsCountIsSet = false;
 bool  TickIsSet() { return nsCountIsSet; }
-void TickSet(int64_t extClock)
-{
-    nsTickCount  = 0;
-    nsFreqCount  = 0;
-    nsTimeCount  = extClock - LPC_TIM1->TC;
-    nsCountIsSet = true;
-}
 
 static volatile int32_t slew = 0; //ns     - up to +/- 2.147s of slew
 int32_t TickGetSlew() { return slew; }
@@ -33,19 +25,58 @@
 void    TickSetPpb (int32_t value) { ppb  = value; LPC_RTC->GPREG0 = ppb; }
 void    TickAddPpb (int32_t value) { ppb += value; LPC_RTC->GPREG0 = ppb; }
 
-static uint32_t lastCall = 0;
+bool TickTicked = false;
+
+/*
++---------+---------------+
+| Seconds |   Base count  |
++---------+---------------+
+|    0    |             0 |
+|    1    |    96,000,000 |
+|   ...   |       ...     |
+|   44    | 4,224,000,000 |
+|   44.74 |          2^32 |
+|   45    |    25,032,704 |
+|   ...   |       ...     |
++---------+---------------+
+*/
+static uint32_t secondsBaseCount = 0;
+
+void TickSet(int64_t extClock)
+{
+    uint32_t       tc = LPC_TIM1->TC;
+    uint32_t  seconds =       tc / TICK_COUNT_PER_SECOND; //0 to 44
+    uint32_t     base =  seconds * TICK_COUNT_PER_SECOND; //0 to 2^32
+    uint32_t fraction =       tc % TICK_COUNT_PER_SECOND; //0 to 96,000,000
+    uint32_t fractionNs = fraction / 96 * 1000;           //0 to 1,000,000,000 which fits into 32 bits
+     int64_t       ns = extClock - fractionNs;
+     
+    __disable_irq();
+             nsTickCount = ns;
+             nsFreqCount = 0;
+             nsTimeCount = 0;
+        secondsBaseCount = base;
+    __enable_irq();
+    
+    nsCountIsSet = true;
+}
 void TickMain()
 {
-    uint32_t sinceLastCall = LPC_TIM1->TC - lastCall;
-    if (sinceLastCall > TICK_COUNT_PER_SECOND)
+    uint32_t sincesecondsBaseCount = LPC_TIM1->TC - secondsBaseCount;
+    if (sincesecondsBaseCount > TICK_COUNT_PER_SECOND)
     { 
         __disable_irq();
-           lastCall += TICK_COUNT_PER_SECOND;
-        nsTickCount += ONE_BILLION;
-        nsFreqCount += ppb;
-        nsTimeCount += slew;
-               slew  = 0;
+        secondsBaseCount += TICK_COUNT_PER_SECOND;
+             nsTickCount += ONE_BILLION;
+             nsFreqCount += ppb;
+             nsTimeCount += slew;
         __enable_irq();
+        slew  = 0;
+        TickTicked = true;
+    }
+    else
+    {
+        TickTicked = false;
     }
 }
 static volatile  int64_t nsTickSnapshot;
@@ -55,7 +86,7 @@
 
 void TickSaveSnapshotI()
 {
-     timerSnapshot = LPC_TIM1->TC - lastCall;
+     timerSnapshot = LPC_TIM1->TC - secondsBaseCount;
     nsTickSnapshot = nsTickCount;
     nsFreqSnapshot = nsFreqCount;
     nsTimeSnapshot = nsTimeCount;
@@ -92,12 +123,10 @@
      int64_t freqNs;
      int64_t timeNs;
     
-    __disable_irq();
-        timerCount = LPC_TIM1->TC - lastCall;
-         tickNs    = nsTickCount;
-         freqNs    = nsFreqCount;
-         timeNs    = nsTimeCount;
-    __enable_irq();
+    timerCount = LPC_TIM1->TC - secondsBaseCount;
+     tickNs    = nsTickCount;
+     freqNs    = nsFreqCount;
+     timeNs    = nsTimeCount;
     
     makeTimesFromCounts(timerCount, tickNs, freqNs, timeNs, pNsInt, pNsAbs);
 }

--- a/tick.h	Wed Jan 17 20:42:14 2018 +0000
+++ b/tick.h	Thu Jan 18 18:07:30 2018 +0000
@@ -15,6 +15,8 @@
 extern uint32_t TickTimerCount(uint32_t startCount);
 extern uint32_t TickTimerMs   (uint32_t startCount);
 
+extern bool     TickTicked;
+
 extern void     TickInit(void);
 extern void     TickMain(void);