pccTimer.c
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上传日期:2008-05-12
资源大小:23136k
文件大小:16k
源码类别:
VxWorks
开发平台:
C/C++
- /* pccTimer.c - PCC Timer library */
- /* Copyright 1984-1996 Wind River Systems, Inc. */
- #include "copyright_wrs.h"
- /*
- modification history
- --------------------
- 01i,22jul96,dat merged with timestamp driver.
- 01h,06jun96,wlf doc: cleanup.
- 01g,16apr94,dzb changed the file name from pccTimer.c to pccTimerTS.c
- 01f,07apr94,dzb optimized timestamp routines.
- 01e,10jan94,dzb added conditional compilation for INCLUDE_TIMESTAMP macro.
- 01d,17sep93,dzb added timestamp support.
- 01c,07jul92,ccc changed genericTimer.h to timerDev.h.
- 01b,26jun92,ccc changed include to genericTimer.h.
- 01a,10jun92,ccc created by moving routines from sysLib.c of mv147, ansified.
- */
- /*
- DESCRIPTION
- This library contains routines to manipulate the timer functions on the
- PCC chip with a board-independent interface. This library handles both
- the system clock and the auxiliary clock functions.
- The macros SYS_CLK_RATE_MIN, SYS_CLK_RATE_MAX, AUX_CLK_RATE_MIN, and
- AUX_CLK_RATE_MAX must be defined to provide parameter checking for the
- sys[Aux]ClkRateSet() routines.
- To include the timestamp timer facility, the macro INCLUDE_TIMESTAMP must be
- defined. When the timestamp timer is running, tick timer #2 is reset every
- system clock interrupt in an effort to control time skew. Note that changing
- the system clock rate will affect the timestamp timer period, which can be
- read by calling sysTimestampPeriod().
- NOTE: the auxiliary clock and timestamp timer share the same physical timer
- (tick timer #2). Only one of these facilities may used at a time. The
- applicable disable routine (sysAuxClkDisable() or sysTimestampDisable())
- can be used to relinquish control of tick timer #2, and the other facility
- may then be enabled. If either clock is active, attempting to activate
- the other clock will fail.
- */
- #include "drv/timer/timerDev.h"
- #include "drv/timer/timestampDev.h"
- /* Locals */
- #define TICK_FREQ 160000
- LOCAL int sysClkTicksPerSecond = 60;
- LOCAL BOOL sysClkRunning = FALSE;
- LOCAL FUNCPTR sysClkRoutine = NULL;
- LOCAL int sysClkArg = NULL;
- LOCAL BOOL sysClkConnected = FALSE;
- LOCAL int auxClkTicksPerSecond = 60;
- LOCAL BOOL sysAuxClkRunning = FALSE;
- LOCAL FUNCPTR sysAuxClkRoutine = NULL;
- LOCAL int sysAuxClkArg = NULL;
- LOCAL BOOL auxClkConnected = FALSE;
- LOCAL BOOL sysTimestampRunning = FALSE; /* running flag */
- /*******************************************************************************
- *
- * sysClkInt - handle system clock interrupts
- *
- * This routine handles system clock interrupts.
- */
- LOCAL void sysClkInt (void)
- {
- /* reset clock interrupt */
- /* clear overflow counter, enable & start counter */
- *TIC_1_CSR = TIC_1_CSR_CLR_OVF |
- TIC_1_CSR_ENABLE;
- *TIC_1_INT_CTL = INT_LVL_TIC_1 |
- TIC_1_INT_CTL_CLEAR |
- TIC_1_INT_CTL_ENABLE; /* reset & enable int, set level */
- #ifdef INCLUDE_TIMESTAMP
- if (sysTimestampRunning) /* sync up timestamp timer */
- sysTimestampEnable ();
- #endif /* INCLUDE_TIMESTAMP */
- if (sysClkRoutine != NULL)
- (*sysClkRoutine) (sysClkArg);
- }
- /*******************************************************************************
- *
- * sysClkConnect - connect a routine to the system clock interrupt
- *
- * This routine specifies the interrupt service routine to be called at each
- * clock interrupt. Normally, it is called from usrRoot() in usrConfig.c to
- * connect usrClock() to the system clock interrupt.
- *
- * RETURN: OK, or ERROR if the routine cannot be connected to the interrupt.
- *
- * SEE ALSO: intConnect(), usrClock(), sysClkEnable()
- */
- STATUS sysClkConnect
- (
- FUNCPTR routine, /* routine called at each system clock interrupt */
- int arg /* argument with which to call routine */
- )
- {
- sysHwInit2 (); /* XXX for now -- needs to be in usrConfig.c */
- sysClkConnected = TRUE;
- sysClkRoutine = routine;
- sysClkArg = arg;
- return (OK);
- }
- /*******************************************************************************
- *
- * sysClkDisable - turn off system clock interrupts
- *
- * This routine disables system clock interrupts.
- *
- * RETURNS: N/A
- *
- * SEE ALSO: sysClkEnable()
- */
- void sysClkDisable (void)
- {
- if (sysClkRunning)
- {
- /* disable interrupts */
- *TIC_1_INT_CTL = TIC_1_INT_CTL_DISABLE;
- sysClkRunning = FALSE;
- }
- }
- /*******************************************************************************
- *
- * sysClkEnable - turn on system clock interrupts
- *
- * This routine enables system clock interrupts.
- *
- * RETURNS: N/A
- *
- * SEE ALSO: sysClkConnect(), sysClkDisable(), sysClkRateSet()
- */
- void sysClkEnable (void)
- {
- if (!sysClkRunning)
- {
- /* preload the preload register */
- *TIC_1_PRELOAD = (short) (65536 - (TICK_FREQ / sysClkTicksPerSecond));
- /* enable the clock interrupt. */
- *TIC_1_CSR = TIC_1_CSR_STOP; /* load counter from preload register */
- /* clear overflow counter, enable & start counter */
- *TIC_1_CSR = TIC_1_CSR_CLR_OVF |
- TIC_1_CSR_ENABLE;
- *TIC_1_INT_CTL = TIC_1_INT_CTL_CLEAR |
- TIC_1_INT_CTL_ENABLE |
- INT_LVL_TIC_1; /* reset&enable int, set level */
- sysClkRunning = TRUE;
- }
- }
- /*******************************************************************************
- *
- * sysClkRateGet - get the system clock rate
- *
- * This routine returns the system clock rate.
- *
- * RETURNS: The number of ticks per second of the system clock.
- *
- * SEE ALSO: sysClkEnable(), sysClkRateSet()
- */
- int sysClkRateGet (void)
- {
- return (sysClkTicksPerSecond);
- }
- /********************************************************************************
- * sysClkRateSet - set the system clock rate
- *
- * This routine sets the interrupt rate of the system clock.
- * It is called by usrRoot() in usrConfig.c.
- *
- * RETURNS: OK, or ERROR if the tick rate is invalid or the timer cannot be
- * set.
- *
- * SEE ALSO: sysClkEnable(), sysClkRateGet()
- */
- STATUS sysClkRateSet
- (
- int ticksPerSecond /* number of clock interrupts per second */
- )
- {
- if (ticksPerSecond < SYS_CLK_RATE_MIN || ticksPerSecond > SYS_CLK_RATE_MAX)
- return (ERROR);
- sysClkTicksPerSecond = ticksPerSecond;
- if (sysClkRunning)
- {
- sysClkDisable ();
- sysClkEnable ();
- }
- return (OK);
- }
- /*******************************************************************************
- *
- * sysAuxClkInt - handle auxiliary clock interrupts
- */
- LOCAL void sysAuxClkInt (void)
- {
- /* reset clock interrupt */
- /* clear overflow counter, enable & start counter */
- *TIC_2_CSR = TIC_2_CSR_CLR_OVF |
- TIC_2_CSR_ENABLE;
- *TIC_2_INT_CTL = TIC_2_INT_CTL_CLEAR |
- TIC_2_INT_CTL_ENABLE |
- INT_LVL_TIC_2; /* reset & enable int, set level */
- if (sysAuxClkRoutine != NULL)
- (*sysAuxClkRoutine) (sysAuxClkArg);
- }
- /*******************************************************************************
- *
- * sysAuxClkConnect - connect a routine to the auxiliary clock interrupt
- *
- * This routine specifies the interrupt service routine to be called at each
- * auxiliary clock interrupt. It does not enable auxiliary clock
- * interrupts.
- *
- * RETURNS: OK, or ERROR if the routine cannot be connected to the interrupt.
- *
- * SEE ALSO: intConnect(), sysAuxClkEnable()
- */
- STATUS sysAuxClkConnect
- (
- FUNCPTR routine, /* routine called at each aux clock interrupt */
- int arg /* argument to auxiliary clock interrupt routine */
- )
- {
- auxClkConnected = TRUE;
- sysAuxClkRoutine = routine;
- sysAuxClkArg = arg;
- return (OK);
- }
- /*******************************************************************************
- *
- * sysAuxClkDisable - turn off auxiliary clock interrupts
- *
- * This routine disables auxiliary clock interrupts.
- *
- * RETURNS: N/A
- *
- * SEE ALSO: sysAuxClkEnable()
- */
- void sysAuxClkDisable (void)
- {
- if ((sysAuxClkRunning) && (!sysTimestampRunning))
- {
- /* clear overflow counter & stop counter */
- *TIC_2_CSR = TIC_2_CSR_CLR_OVF |
- TIC_2_CSR_STOP;
- /* reset & disable int, set level */
- *TIC_2_INT_CTL = TIC_2_INT_CTL_CLEAR |
- TIC_2_INT_CTL_DISABLE;
- sysAuxClkRunning = FALSE;
- }
- }
- /*******************************************************************************
- *
- * sysAuxClkEnable - turn on auxiliary clock interrupts
- *
- * This routine enables auxiliary clock interrupts.
- *
- * RETURNS: N/A
- *
- * SEE ALSO: sysAuxClkConnect(), sysAuxClkDisable(), sysAuxClkRateSet()
- */
- void sysAuxClkEnable (void)
- {
- if ((!sysAuxClkRunning) && (!sysTimestampRunning))
- {
- /* preload the preload register */
- *TIC_2_PRELOAD = (short) (65536 - (TICK_FREQ / auxClkTicksPerSecond));
- /* enable the clock interrupt */
- *TIC_2_CSR = TIC_2_CSR_STOP; /* load counter from preload reg */
- /* clear overflow counter, enable & start counter */
- *TIC_2_CSR = TIC_2_CSR_CLR_OVF |
- TIC_2_CSR_ENABLE;
- *TIC_2_INT_CTL = TIC_2_INT_CTL_CLEAR |
- TIC_2_INT_CTL_ENABLE |
- INT_LVL_TIC_2; /* reset&enable int, set level */
- sysAuxClkRunning = TRUE;
- }
- }
- /*******************************************************************************
- *
- * sysAuxClkRateGet - get the auxiliary clock rate
- *
- * This routine returns the interrupt rate of the auxiliary clock.
- *
- * RETURNS: The number of ticks per second of the auxiliary clock.
- *
- * SEE ALSO: sysAuxClkEnable(), sysAuxClkRateSet()
- */
- int sysAuxClkRateGet (void)
- {
- return (auxClkTicksPerSecond);
- }
- /*******************************************************************************
- *
- * sysAuxClkRateSet - set the auxiliary clock rate
- *
- * This routine sets the interrupt rate of the auxiliary clock.
- * It does not enable auxiliary clock interrupts.
- *
- * RETURNS: OK, or ERROR if the tick rate is invalid or the timer cannot be set.
- *
- * SEE ALSO: sysAuxClkEnable(), sysAuxClkRateGet()
- */
- STATUS sysAuxClkRateSet
- (
- int ticksPerSecond /* number of clock interrupts per second */
- )
- {
- if (sysTimestampRunning)
- return (ERROR);
- if (ticksPerSecond < AUX_CLK_RATE_MIN || ticksPerSecond > AUX_CLK_RATE_MAX)
- return (ERROR);
- auxClkTicksPerSecond = ticksPerSecond;
- if (sysAuxClkRunning)
- {
- sysAuxClkDisable ();
- sysAuxClkEnable ();
- }
- return (OK);
- }
- #ifdef INCLUDE_TIMESTAMP
- /*******************************************************************************
- *
- * sysTimestampConnect - connect a user routine to the timestamp timer interrupt
- *
- * This routine usually specifies the user interrupt routine to be called at
- * each timestamp timer interrupt. In this case, however, the timestamp timer
- * interrupt is not used since the timer is reset by the system clock before
- * an interrupt can be generated.
- *
- * RETURNS: OK, or ERROR if sysTimestampInt() interrupt handler is not used.
- */
- STATUS sysTimestampConnect
- (
- FUNCPTR routine, /* routine called at each timestamp timer interrupt */
- int arg /* argument with which to call routine */
- )
- {
- return (ERROR);
- }
- /*******************************************************************************
- *
- * sysTimestampEnable - initialize and enable the timestamp timer
- *
- * This routine disables the timestamp timer interrupt and initializes the
- * counter registers. If the timestamp timer is already running, this routine
- * merely resets the timer counter.
- *
- * The rate of the timestamp timer should be set explicitly within the BSP,
- * in the sysHwInit() routine. This routine does not intialize the timer
- * rate.
- *
- * RETURNS: OK, or ERROR if the timestamp timer cannot be enabled.
- */
- STATUS sysTimestampEnable (void)
- {
- if (sysTimestampRunning)
- {
- *TIC_2_CSR = TIC_2_CSR_STOP; /* clear the counter */
- *TIC_2_CSR = TIC_2_CSR_ENABLE; /* enable the timer */
- return (OK);
- }
- if ((sysAuxClkRunning) || (!sysClkRunning))
- return (ERROR);
- sysTimestampRunning = TRUE;
- /*
- * Disable the timer interrupt. The timestamp timer is reset by the
- * system clock before rollover occurs.
- */
- *TIC_2_INT_CTL = TIC_2_INT_CTL_DISABLE;
- *TIC_2_PRELOAD = 0x0; /* highest period -> freerunning */
- *TIC_2_CSR = TIC_2_CSR_STOP; /* clear the counter */
- *TIC_2_CSR = TIC_2_CSR_ENABLE; /* enable the timer */
- return (OK);
- }
- /*******************************************************************************
- *
- * sysTimestampDisable - disable the timestamp timer
- *
- * This routine disables the timestamp timer. Interrupts are not disabled,
- * although the tick counter will not increment after the timestamp timer
- * is disabled, thus interrupts will no longer be generated.
- *
- * RETURNS: OK, or ERROR if the timestamp timer cannot be disabled.
- */
- STATUS sysTimestampDisable (void)
- {
- if (sysAuxClkRunning)
- return (ERROR);
- if (sysTimestampRunning)
- {
- sysTimestampRunning = FALSE;
- *TIC_2_CSR = TIC_2_CSR_DISABLE; /* disable the timer */
- }
- return (OK);
- }
- /*******************************************************************************
- *
- * sysTimestampPeriod - get the timestamp timer period
- *
- * This routine returns the period of the timestamp timer in ticks.
- * The period, or terminal count, is the number of ticks to which the timestamp
- * timer will count before rolling over and restarting the counting process.
- *
- * RETURNS: The period of the timestamp timer in counter ticks.
- */
- UINT32 sysTimestampPeriod (void)
- {
- return (TICK_FREQ / sysClkTicksPerSecond);
- }
- /*******************************************************************************
- *
- * sysTimestampFreq - get the timestamp timer clock frequency
- *
- * This routine returns the frequency of the timer clock, in ticks per second.
- * The rate of the timestamp timer should be set explicitly within the BSP,
- * in the sysHwInit() routine.
- *
- * RETURNS: The timestamp timer clock frequency, in ticks per second.
- */
- UINT32 sysTimestampFreq (void)
- {
- UINT32 timerFreq;
- timerFreq = TICK_FREQ;
- return (timerFreq);
- }
- /*******************************************************************************
- *
- * sysTimestamp - get the timestamp timer tick count
- *
- * This routine returns the current value of the timestamp timer tick counter.
- * The tick count can be converted to seconds by dividing by the return of
- * sysTimestampFreq().
- *
- * This routine should be called with interrupts locked. If interrupts are
- * not already locked, sysTimestampLock() should be used instead.
- *
- * RETURNS: The current timestamp timer tick count.
- *
- * SEE ALSO: sysTimestampLock()
- */
- UINT32 sysTimestamp (void)
- {
- UINT32 tick = 0;
- register short * pCounter;
- if (sysTimestampRunning)
- {
- pCounter = TIC_2_COUNTER;
- *TIC_2_CSR = TIC_2_CSR_DISABLE; /* disable the timer */
- tick = *pCounter; /* read tick counter value */
- *TIC_2_CSR = TIC_2_CSR_ENABLE; /* enable the timer */
- tick &= 0x0000ffff;
- }
- return (tick);
- }
- /*******************************************************************************
- *
- * sysTimestampLock - get the timestamp timer tick count
- *
- * This routine returns the current value of the timestamp timer tick counter.
- * The tick count can be converted to seconds by dividing by the return of
- * sysTimestampFreq().
- *
- * This routine locks interrupts for cases where it is necessary to stop the
- * tick counter in order to read it, or when two independent counters must
- * be read. If interrupts are already locked, sysTimestamp() should be
- * used instead.
- *
- * RETURNS: The current timestamp timer tick count.
- *
- * SEE ALSO: sysTimestamp()
- */
- UINT32 sysTimestampLock (void)
- {
- UINT32 tick = 0;
- register short * pCounter;
- int lockKey;
- if (sysTimestampRunning)
- {
- pCounter = TIC_2_COUNTER;
- lockKey = intLock (); /* LOCK INTERRUPTS */
- *TIC_2_CSR = TIC_2_CSR_DISABLE; /* disable the timer */
- tick = *pCounter; /* read tick counter value */
- *TIC_2_CSR = TIC_2_CSR_ENABLE; /* enable the timer */
- intUnlock (lockKey); /* UNLOCK INTERRUPTS */
- tick &= 0x0000ffff;
- }
- return (tick);
- }
- #endif /* INCLUDE_TIMESTAMP */