/* File: TIMER.C */

/****************************************************************************
*
* STK16XSW.TIMER
* ==============
*
* Timer routines
*                 
* TQ-Systems GmbH                                                         
* ---------------                                                         
* Customer: TQ-Components
* Project : STK16XSW
* Tools   : uVision 2.05
*
* 
* Rev: Date:     Name:            Modification:
* ----+---------+----------------+------------------------------------------
* 100  16.01.01  A. Lichte        taken over from STK16X.506                
*****************************************************************************/

/****************************************************************************
*
*                             availability summary
*
* available for Starterkit: STK16X STK16XU
* conformed for Starterkit: STK16X 
* available for Modul     : TQM164   TQM165   TQM165U  TQM166  TQM167
*                           TQM167LC TQM167U  TQM167UL
* conformed for Modul     : TQM164   TQM165   TQM165U  TQM166  TQM167
*                           TQM167LC TQM167U  TQM167UL
*****************************************************************************/

/*==========================================================================*
* pragmas:
*===========================================================================*/

/*=========================================================================*
* include files (#INCLUDE):
*==========================================================================*/
/*-------------------------------------------------------------------------*
* standard include files:
*--------------------------------------------------------------------------*/
#include <stdio.h>              /* standard I/O functions    */
#include <ctype.h>              /* typecast functions        */
#include <string.h>             /* String functions          */
#include <setjmp.h>             /* global jump functions     */
#include <absacc.h>             /* absolute accesss          */
#include <intrins.h>            /* intrinsic functions       */
#include <reg167.h>             /* Special function register */

/*-------------------------------------------------------------------------*
* project specific include files:
*--------------------------------------------------------------------------*/
#include "timer.h"              /* timer functions           */

/*=========================================================================*
* modul internal definitions (#DEFINE):
*==========================================================================*/
#define T3_ICTRL     T3IC^6     /* timer 3 interrupt control bit */

/*=========================================================================*
* modul internal type definitions(TYPEDEF):
*==========================================================================*/

/*=========================================================================*
* modul internal constants (CONST):
*==========================================================================*/

/*=========================================================================*
* extern available constants (CONST):
*==========================================================================*/

/*=========================================================================*
* modul internal variables:
*==========================================================================*/
TIMER_COUNTER idata timer_counter;    /* 10 ms counter variable           */
t_timer_idle_func   timer_idle_func;  /* idle function for timer interrupt*/
unsigned int        timer_looptime;

sbit t3_ictrl = T3_ICTRL;             /* timer 3 interrupt control bit    */

/*=========================================================================*
* global extern available variables (EXTERN):
*==========================================================================*/

/*=========================================================================*
* modul internal functions:
*==========================================================================*/

/*-------------------------------------------------------------------------*
* void timer3_int(void) interrupt 0x23
*--------------------------------------------------------------------------*
* FT: interrupt service routine for timer 3 over/underflow interrupt
* EP: -
* RW: -
* GP: timer_idlefunc = pointer to idle function for timer interrupt
*--------------------------------------------------------------------------*/
void timer3_int(void) interrupt 0x23
{
  timer_counter++;
  
  if (timer_idle_func) (*timer_idle_func) ();
}

/*=========================================================================*
* extern available functions:
*==========================================================================*/

/*--------------------------------------------------------------------------*
* BOOL timer_init(t_timer_idle_func idle_func)                            
*---------------------------------------------------------------------------*
* FT: init timer 3 time base; calculation refers to CPU frequency (20 MHz)
* EP: idlefunc = pointer to idle function, called  from interrupt service 
*                routine (NULL if not used)
* RW: TRUE = function succesfully; FALSE= function failed
* GP: 
*---------------------------------------------------------------------------*/
BOOL timer_init(t_timer_idle_func idle_func)
{ USHORT i, j;
    
  /* init timer 3:  */
  T2CON = 0x0027;          /* reload timer 2 at over/underflow of timer 3 */
  T3CON = 0x0080;            /* timer  mode: 400 ns time base, count down */
  T2    = 25000;              /* init timer 2 register: 10 ms T2 overflow */
  T3    = 25000;              /* init timer 3 register: 10 ms T3 overflow */
  T3IC  = T3INT_INI;           /* init timer 3 interrupt control register */
  T3R   = 1;                 /* init timer 3 enable register: 1 = running */

  timer_counter = TIMER_MIN;                          /* init 10 ms timer */
  IEN = 1;                                    /* general interrupt enable */

  *timer_idle_func = idle_func;                     /* init idle function */

  /* detect number of loops for 20 us delay: */
  for (i=0; i<0x3FF; i++)              /* time measurement for 3FFh loops */
  {
    for (j=0; j<1000; j++) _nop_();     /* 1000 x deceleration (us -> ms) */
  }                                 

  if ((timer_counter > 0x1FF) || (timer_counter < 0x04))
  { 
    timer_looptime=0xFF; return (FALSE);          /* initialization failed */
  } 

  /* get loops for 20 us counter (offset 2 for compensation of outer loop):*/
  timer_looptime = 0x7FF / timer_counter - 2; 

  return (TRUE);
} 

/*--------------------------------------------------------------------------*
* void timer_reset(void)
*---------------------------------------------------------------------------*
* FT: reset timer counter
* EP:  -
* RW: -
* GP: -
*---------------------------------------------------------------------------*/
void timer_reset(void)
{
  t3_ictrl = 0;     /* disable timer 3 interrupt (32 bit variable access) */
  timer_counter = TIMER_MIN;                          /* init 10 ms timer */
  t3_ictrl = 1;                            /* re-enable timer 3 interrupt */
}

/*--------------------------------------------------------------------------*
* TIMER_COUNTER timer_get_10ms(TIMER_COUNTER base_time)
*---------------------------------------------------------------------------*
* FT: calculate time difference between parameter t and current time
* EP: base_time = base time for calculate time difference 
* RW: -
* GP: -
*---------------------------------------------------------------------------*/
TIMER_COUNTER timer_get_10ms(TIMER_COUNTER t)
{ TIMER_COUNTER val;

  t3_ictrl = 0;     /* disable timer 3 interrupt (32 bit variable access) */
  val = timer_counter - t;                   /* calculate time difference */
  t3_ictrl = 1;                            /* re-enable timer 3 interrupt */

  return (val);
}

/*--------------------------------------------------------------------------*
* void timer_delay_10ms(TIMER_COUNTER len)
*---------------------------------------------------------------------------*
* FT: generate delay for len x 10 ms 
* EP: len = amount of 10 ms ticks (result of len = 0 may be 0..1)
* RW: -
* GP: -
*---------------------------------------------------------------------------*/
void timer_delay_10ms(TIMER_COUNTER len)
{ TIMER_COUNTER base_time;

  base_time = timer_get_10ms(0);
  while (timer_get_10ms(base_time) < len);
}


/*--------------------------------------------------------------------------*
* void timer_delay_20us(USHORT len)
*---------------------------------------------------------------------------*
* FT: generate delay for len x 20 us 
* EP: len = amount of 20 us ticks
* RW: -
* GP: -
*---------------------------------------------------------------------------*/
void timer_delay_20us(USHORT len)
{ USHORT i, j;

  for (i=0; i<len; i++)                         /* number of 20 us delays */
  {
     for (j=0; j<timer_looptime; j++);                  /* wait for 20 us */
  }
}