timer.c

intel xscale pxa270的完整wince4.2 BSP包

/******************************************************************************
* FileName:  timer.c - Time and Date.
*
* SanDisk Host Developer's Toolkit
*
* Copyright (c) 1997 - 1999 SanDisk Corporation
* All rights reserved.
*
******************************************************************************/
/* timer.c - Timer service routines for run-time drivers.
*
*  These routines provide executive services for the run-time drivers
*  running on a PC with no executive kernel. Equivalent services should
*  be provided by the kernel environment, replacing these.
*
* The following functions must be provided
* 
* SDVOID  oem_getsysdate()          - Date and time information
* ULONG platform_get_ticks()      - Return the current system tick count
* ULONG platform_ticks_per_second()    - Return the tick period
* 
*/          

#include <windows.h>
#include <winbase.h>

#include "oem.h"




#define TICKS_PER_SECOND        18

ULONG delayTime = 0L;

DWORD CurMSec;


/* ======================= Timer management functions ===================== */

/****************************************************************************
** Name:  PLATFORM_TICK_P_SECOND - Get current tick per second (USER SUPPLIED)
**
** Summary:
**
**    #include "oem.h"
**
**    platform_tick_p_second(SDVOID)
**
** Description:
**       Provide a way to get the number of ticks per second.
**       The default is 18 ticks per second for INTEL platform
**       and 60 ticks per second for other platforms.
**
**
**    NOTE: Be sure to retain the property of returning its argument. The 
**            package depends on it.
**
** Entries:
**    None
**
** Returns
**    The ticks per second.
**
**
*****************************************************************************/
ULONG platform_ticks_p_second(SDVOID) /*__fn__*/
{
        return(TICKS_PER_SECOND);
}


/****************************************************************************
** Name:  PLATFORM_DELAYMS - delay in certain time (USER SUPPLIED)
**
** Summary:
**
**    #include "oem.h"
**
**    platform_delayms(SDVOID)
**
** Description:
**    Wait for a certain time requested by the user
**
** Entries:
**    sleep     The granularity in miliseconds
**
** Returns
**    None.
**
** Example:
**    #include "oem.h"
**
** Note:
** The calculation of the ticks at a given delay time in millisecond is:
**      one tick in millisecond = 1000 millisecond / TICKS_PER_SECOND
**      no. ticks = (delay time in millisecond) / (onetick in millisecond)
**
*****************************************************************************/
SDVOID platform_delayms(COUNT delay_millis) /*__fn__*/
{
        ULONG tticks, tcurr;

        tcurr = platform_get_ticks();
        tticks = tcurr + (ULONG)(delay_millis / (1000 / TICKS_PER_SECOND));

    /* Wait for awhile */
        while (tcurr <= tticks)
        {
                if (tcurr > platform_get_ticks())
                {
                        tticks = 1L + platform_get_ticks();
                }

                tcurr = platform_get_ticks();
        }
}


/****************************************************************************
** Name:  PLATFORM_GET_TICKS - Get current timer tick (USER SUPPLIED)
**
** Summary:
**
**    #include "oem.h"
**
**    platform_get_ticks(SDVOID)
**
** Description:
**    Provide a way to get the current timer tick.
**
** Entries:
**    None
**
** Returns
**    The granularity timer ticks.
**
** Example:
**    #include "oem.h"
**
**
*****************************************************************************/
ULONG platform_get_ticks(SDVOID) /*__fn__*/
{
        ULONG myTicks;
        ULONG WorkTicks;



    WorkTicks=GetTickCount();
    myTicks=WorkTicks;


/*Since this code was originally developed on a PC with the old 55ms 
  timer, even a delay of 1ms was potentially 55ms. Delays used in the
  code issued via OS_WAIT(n) may need a 55ms tick. You can try playing
  with values in the following loop if necessary -- or remove the
  loop entirely if everything is working*/

   
    while(myTicks <= WorkTicks + 3)
                    myTicks=GetTickCount();    

  

        return(myTicks);
}