time.c

* DEFINITION * This a set of math functions that deal with time. The functions accept * 4-digit

/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
 *
 *  Copyright (c) 2007 by Qu chun lei [e-mail]
 *
 *  Filename:  TIME.C
 *  Module:    0404C
 *  Language:  ANSI C
 *  $Revision: 18 $
 *
 *  Math and conversion functions which operate on time values.  For details
 *  see TIME.H.
 *
 * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */

#ifndef TIME_C
#define TIME_C

/*------------------------*
 |  Include header files
 *------------------------*/

#include "time.h"

/*-------------*
 |  Constants
 *-------------*/

#define TIME_MAX  0xFFFF

/*-------------------------------*
 |  Private function prototypes
 *-------------------------------*/

#if TIME_OF_DAY_ADD || TIME_ADD
static TTime TimeAddMod(TTime t1, TTime t2, UINT8 modulus);
#endif
#if TIME_OF_DAY_SUBTRACT || TIME_SUBTRACT
static TTime TimeSubtractMod(TTime t1, TTime t2, UINT8 modulus);
#endif

#if TIME_OF_DAY_ADD || TIME_ADD || TIME_OF_DAY_SUBTRACT || TIME_SUBTRACT
static TTimeOfDay TimeOfDayCalculate(TTimeOfDay t1, TTime t2, 
    TTimeOfDayFormat tt, BOOLEAN addition);
static TTime TimeCalculate(TTime t1, TTime t2, BOOLEAN addition);
#endif


/*--------------------*
 |  Public functions
 *--------------------*/

/*---------------------------------------------------------------------------*
 |  TimeOfDayAdd
 |
 |  For details see TIME.H
 *---------------------------------------------------------------------------*/

#if TIME_OF_DAY_ADD
TTimeOfDay TimeOfDayAdd(TTimeOfDay t1, TTime t2, TTimeOfDayFormat tt)
{
   return TimeOfDayCalculate(t1, t2, tt, 1);
}
#endif


/*---------------------------------------------------------------------------*
 |  TimeOfDaySubtract
 |
 |  day value.
 |  For details see TIME.H
 *---------------------------------------------------------------------------*/

#if TIME_OF_DAY_SUBTRACT
TTimeOfDay TimeOfDaySubtract(TTimeOfDay t1, TTime t2, TTimeOfDayFormat tt)
{
   return TimeOfDayCalculate(t1, t2, tt, 0);
}
#endif


/*---------------------------------------------------------------------------*
 |  TimeAdd
 |
 |  For details see TIME.H
 *---------------------------------------------------------------------------*/

#if TIME_ADD
TTime TimeAdd(TTime t1, TTime t2)
{
   return TimeCalculate(t1, t2, 1);
}
#endif


/*---------------------------------------------------------------------------*
 |  TimeSubtract
 |
 |  For details see TIME.H
 *---------------------------------------------------------------------------*/

#if TIME_SUBTRACT
TTime TimeSubtract(TTime t1, TTime t2)
{
   return TimeCalculate(t1, t2, 0);
}
#endif


/*---------------------------------------------------------------------------*
 |  TimeCorrectFormat
 |
 |  For details see TIME.H
 *---------------------------------------------------------------------------*/

#if TIME_CORRECT_FORMAT
TTime TimeCorrectFormat(TTime timeValue)
{
   TTime result;
/* bcd digit check */
   if(((timeValue & 0xF000) > 0x9000) || ((timeValue & 0x0F00) > 0x0900) ||
      ((timeValue & 0x00F0) > 0x0090) || ((timeValue & 0x000F) > 0x0009))
   {
      result = TIME_ERROR;
   }
   else
   {   /* if 2 ls digits > 59, subtract 60, add 1 to 2 ms digits */
      if((timeValue & 0x00f0) > 0x0050)
      {
         timeValue -= 0x0060;
         timeValue += 0x0100;
         if((timeValue & 0x0f00) > 0x0900)
         {
            timeValue -= 0x0A00;
            timeValue += 0x1000;
         }
      }

      if((timeValue & 0xFF00) > 0x9900)   /* Check overflow in 2 MSD's */
         result = TIME_ERROR;
      else
         result = timeValue;
   }
   return(result);
}
#endif


/*---------------------------------------------------------------------------*
 |  TimeValid
 |
 |  For details see TIME.H
 *---------------------------------------------------------------------------*/

#if TIME_VALID
BOOLEAN TimeValid(TTime timeValue)
{
   BOOLEAN result;
/* bcd digit check, ls 2 digits must be <= 59 */
   if(((timeValue & 0xF000) > 0x9000) || ((timeValue & 0x0F00) > 0x0900) ||
      ((timeValue & 0x00F0) > 0x0050) || ((timeValue & 0x000F) > 0x0009))
   {
      result = FALSE;
   }
   else
   {
      result = TRUE;
   }

   return(result);
}
#endif


/*---------------------------------------------------------------------------*
 |  TimeOfDayValid
 |
 |  For details see TIME.H
 *---------------------------------------------------------------------------*/

#if TIME_OF_DAY_VALID
BOOLEAN TimeOfDayValid(TTimeOfDay timeValue, TTimeOfDayFormat tt)
{
   BOOLEAN result;
                              /* BCD digit check, ls 2 digits must be <= 59 */
   if(((timeValue & 0xF000) > 0x9000) || ((timeValue & 0x0F00) > 0x0900) ||
      ((timeValue & 0x00F0) > 0x0050) || ((timeValue & 0x000F) > 0x0009))
   {
      result = FALSE;
   }
   else
   {
      timeValue &= 0xFF00;             /* Range check */

      if(tt == TIME_12_HOUR)
      {
         if((timeValue < 0x0100) || (timeValue > 0x1200))
            result = FALSE;
         else
            result = TRUE;
      }
      else
      {
         if(timeValue > 0x2300)
            result = FALSE;
         else
            result = TRUE;
      }
   }

   return(result);
}
#endif


/*---------------------------------------------------------------------------*
 |  TimeToBinary
 |
 |  For details see TIME.H
 *---------------------------------------------------------------------------*/

#if TIME_TO_BINARY
UINT16 TimeToBinary(TTime bcdTime)
{
   UINT16 result;

   result = (bcdTime & 0x000f);
   result += (((bcdTime & 0x00F0)/0x0010)*10);
   result += (((bcdTime & 0x0F00)/0x0100)*60);
   result += (((bcdTime & 0xF000)/0x1000)*600);

   return(result);
}
#endif


/*---------------------------------------------------------------------------*
 |  TimeFromBinary
 |
 |  For details see TIME.H
 *---------------------------------------------------------------------------*/

#if TIME_FROM_BINARY
TTime TimeFromBinary(UINT16 binaryTime)
{
   TTime result;
   UINT16 scratch;

   scratch = binaryTime/600;
   result = (scratch * 0x1000);

   binaryTime -= (scratch * 600);
   scratch = binaryTime/60;
   result += (scratch * 0x0100);

   binaryTime -= (scratch * 60);
   scratch = binaryTime/10;
   result += (scratch * 0x0010);

   binaryTime -= (scratch * 10);
   result += binaryTime;

   return(result);
}
#endif

/*---------------------------------------------------------------------------*
 |  Time12ToBinary
 |
 |  For details see TIME.H
 *---------------------------------------------------------------------------*/

#if TIME_12_TO_BINARY
UINT16 Time12ToBinary(TTime bcdTime)
{
   UINT16 result;

   result = TimeToBinary(bcdTime);
   if(result >= 720)
      result -= 720;

   return(result);
}
#endif


/*---------------------------------------------------------------------------*
 |  Time12FromBinary
 |
 |  For details see TIME.H
 *---------------------------------------------------------------------------*/

#if TIME_12_FROM_BINARY
TTime Time12FromBinary(UINT16 binaryTime)
{
   return TimeFromBinary(binaryTime < 60 ? binaryTime + 720: binaryTime);
}
#endif


/*---------------------*
 |  Private functions
 *---------------------*/

/*---------------------------------------------------------------------------*
 |  TimeAddMod   result = t1 + t2
 |
 |  Add two bcd time values and return a time value.
 |
 |  On Entry:  t1 is the first time value to add
 |             t2 is the second time value to add
 |
 |  On Exit:   Returns the 4-digit sum
 *---------------------------------------------------------------------------*/

#if TIME_OF_DAY_ADD || TIME_ADD
static TTime TimeAddMod(TTime t1, TTime t2, UINT8 modulus)
{
   TTime result;
   UINT16 decimal, carry;
   UINT8 hour1, hour2;

   decimal = (t1 & 0xF) + (t2 & 0xF);        /* Low nibble */
   carry = decimal / 10;
   decimal %= 10;

   result = (t1 & 0xF0) + (t2 & 0xF0) + (carry*0x10);
   carry = result / 0x60;
   result = (result % 0x60) + decimal;       /* Add in low nibble */

   hour1 = (UINT8)(t1/0x100);                         /* Modulus check on high byte */
   hour2 = (UINT8)(t2/0x100);
   decimal = (hour1 & 0xF) + (hour2 & 0xF) + ((hour1/0x10) + (hour2/0x10))*10
            + carry;
   decimal %= modulus;
   result += (decimal % 10 + (decimal / 10) * 0x10)*0x100;

   return result;
}
#endif


/*---------------------------------------------------------------------------*
 |  TimeSubtractMod	result =  t1 - t2
 |
 |  Subtract time from a time  value and return a time value
 |  result = t1 - t2
 |
 |  On Entry:  t1 is the first time value to subtract
 |             t2 is the second time value to subtract
 |
 |  On Exit:   Returns the 4-digit difference
 *---------------------------------------------------------------------------*/

#if TIME_OF_DAY_SUBTRACT || TIME_SUBTRACT
static TTime TimeSubtractMod(TTime t1, TTime t2, UINT8 modulus)
{
   TTime result;
   UINT16 borrow, scratch;

/*-----------*
 |  Minutes
 *-----------*/

   if((result = (t1 & 0xF) - (t2 & 0xF)) > 9)
   {
      borrow = 0x10;
      result += 10;
   }
   else
      borrow = 0;

   if((scratch = (t1 & 0xF0) - (t2 & 0xF0) - borrow) > 0x50)
   {
      scratch += 0x60;
      borrow = 0x100;
   }
   else
      borrow = 0;
   result += scratch;                  /* Result now contains minutes */

/*---------*
 |  Hours
 *---------*/

   scratch =  ((t1&0xF000) / 0x10)*10 + (t1 & 0xF00) - borrow;
   scratch -= ((t2&0xF000) / 0x10)*10 + (t2 & 0xF00);
   while(scratch > (0x100 * modulus))
      scratch += (0x100 * modulus);
   scratch /= 0x100;
   scratch = scratch/10*0x10 + (scratch%10);
   scratch *= 0x100;
   result += scratch;

   return result;
}
#endif


#if TIME_OF_DAY_ADD || TIME_ADD || TIME_OF_DAY_SUBTRACT || TIME_SUBTRACT
/*---------------------------------------------------------------------------*
 |  TimeOfDayCalculate
 |  
 |  Perform math function requested on t1 and t2 and return the result.
 |  If addition then result =  t1 + t2, otherwise result =  t1 - t2
 |
 |  On Entry:  t1 is the first time of day value to calculate
 |             t2 is the second time of day value to calculate
 |
 |  On Exit:   Returns the result in BCD format
 *---------------------------------------------------------------------------*/

static TTimeOfDay TimeOfDayCalculate(TTimeOfDay t1, TTime t2, 
                                     TTimeOfDayFormat tt, BOOLEAN addition)
{
   TTimeOfDay result;
   UINT8 modulus;

   if(TimeOfDayValid(t1, tt) && TimeValid(t2))
   {
      if(tt == TIME_12_HOUR)           /* 1:00-12:00 -> 0:00-11:00 */
      {
         modulus = 12;
         t1 -= 0x0100;
         if((t1 & 0x0F00) > 0x0900)
            t1 -= 0x0600;
      }
      else
         modulus = 24;

      if(addition)
         result = TimeAddMod(t1, t2, modulus);
      else
         result = TimeSubtractMod(t1, t2, modulus);
      
      if(tt == TIME_12_HOUR)           /* 0:00-11:00 -> 1:00-12:00 */
      {
         result += 0x0100;
         if((result & 0x0F00) > 0x0900)
            result += 0x0600;
      }
   }
   else
      result = TIME_ERROR;

   return(result);
}
#endif


#if TIME_OF_DAY_ADD || TIME_ADD || TIME_OF_DAY_SUBTRACT || TIME_SUBTRACT
/*---------------------------------------------------------------------------*
 |  TimeCalculate
 |  
 |  Perform math function requested on t1 and t2 and return the result.
 |  If addition then result =  t1 + t2, otherwise result =  t1 - t2
 |
 |  On Entry:  t1 is the first time value to calculate
 |             t2 is the second time value to calculate
 |
 |  On Exit:   Returns the result in BCD format
 *---------------------------------------------------------------------------*/

static TTime TimeCalculate(TTime t1, TTime t2, BOOLEAN addition)
{
   TTime result;

   if(TimeValid(t1) && TimeValid(t2))
   {
      if(addition)
         result = TimeAddMod(t1, t2, (UINT8) TIME_MAX);
      else
         result = TimeSubtractMod(t1, t2, (UINT8) TIME_MAX);
      if(!TimeValid(result))
         result = TIME_ERROR;
   }
   else
      result = TIME_ERROR;

   return(result);
}
#endif

#endif