timer.c

基于TI公司Cortex-M3的uart超级通信开发

    //
    // Set the stall mode.
    //
    ulTimer &= TIMER_CTL_TASTALL | TIMER_CTL_TBSTALL;
    HWREG(ulBase + TIMER_O_CTL) = (bStall ?
                                   (HWREG(ulBase + TIMER_O_CTL) | ulTimer) :
                                   (HWREG(ulBase + TIMER_O_CTL) & ~(ulTimer)));
}

//*****************************************************************************
//
//! Enable RTC counting.
//!
//! \param ulBase is the base address of the timer module.
//!
//! This function causes the timer to start counting when in RTC mode.  If not
//! configured for RTC mode, this will do nothing.
//!
//! \return None.
//
//*****************************************************************************
void
TimerRTCEnable(unsigned long ulBase)
{
    //
    // Check the arguments.
    //
    ASSERT(TimerBaseValid(ulBase));

    //
    // Enable RTC counting.
    //
    HWREG(ulBase + TIMER_O_CTL) |= TIMER_CTL_RTCEN;
}

//*****************************************************************************
//
//! Disable RTC counting.
//!
//! \param ulBase is the base address of the timer module.
//!
//! This function causes the timer to stop counting when in RTC mode.
//!
//! \return None.
//
//*****************************************************************************
void
TimerRTCDisable(unsigned long ulBase)
{
    //
    // Check the arguments.
    //
    ASSERT(TimerBaseValid(ulBase));

    //
    // Disable RTC counting.
    //
    HWREG(ulBase + TIMER_O_CTL) &= ~(TIMER_CTL_RTCEN);
}

//*****************************************************************************
//
//! Set the timer prescale value.
//!
//! \param ulBase is the base address of the timer module.
//! \param ulTimer specifies the timer(s) to adjust; must be one of \b TIMER_A,
//! \b TIMER_B, or \b TIMER_BOTH.
//! \param ulValue is the timer prescale value; must be between 0 and 255,
//! inclusive.
//!
//! This function sets the value of the input clock prescaler.  The prescaler
//! is only operational when in 16-bit mode and is used to extend the range of
//! the 16-bit timer modes.
//!
//! \return None.
//
//*****************************************************************************
void
TimerPrescaleSet(unsigned long ulBase, unsigned long ulTimer,
                 unsigned long ulValue)
{
    //
    // Check the arguments.
    //
    ASSERT(TimerBaseValid(ulBase));
    ASSERT((ulTimer == TIMER_A) || (ulTimer == TIMER_B) ||
           (ulTimer == TIMER_BOTH));
    ASSERT(ulValue < 256);

    //
    // Set the timer A prescaler if requested.
    //
    if(ulTimer & TIMER_A)
    {
        HWREG(ulBase + TIMER_O_TAPR) = ulValue;
    }

    //
    // Set the timer B prescaler if requested.
    //
    if(ulTimer & TIMER_B)
    {
        HWREG(ulBase + TIMER_O_TBPR) = ulValue;
    }
}

//*****************************************************************************
//
//! Get the timer prescale value.
//!
//! \param ulBase is the base address of the timer module.
//! \param ulTimer specifies the timer; must be one of \b TIMER_A or
//! \b TIMER_B.
//!
//! This function gets the value of the input clock prescaler.  The prescaler
//! is only operational when in 16-bit mode and is used to extend the range of
//! the 16-bit timer modes.
//!
//! \return The value of the timer prescaler.
//
//*****************************************************************************
unsigned long
TimerPrescaleGet(unsigned long ulBase, unsigned long ulTimer)
{
    //
    // Check the arguments.
    //
    ASSERT(TimerBaseValid(ulBase));
    ASSERT((ulTimer == TIMER_A) || (ulTimer == TIMER_B) ||
           (ulTimer == TIMER_BOTH));

    //
    // Return the appropriate prescale value.
    //
    return((ulTimer == TIMER_A) ? HWREG(ulBase + TIMER_O_TAPR) :
           HWREG(ulBase + TIMER_O_TBPR));
}

//*****************************************************************************
//
//! Sets the timer load value.
//!
//! \param ulBase is the base address of the timer module.
//! \param ulTimer specifies the timer(s) to adjust; must be one of \b TIMER_A,
//! \b TIMER_B, or \b TIMER_BOTH.  Only \b TIMER_A should be used when the
//! timer is configured for 32-bit operation.
//! \param ulValue is the load value.
//!
//! This function sets the timer load value; if the timer is running then the
//! value will be immediately loaded into the timer.
//!
//! \return None.
//
//*****************************************************************************
void
TimerLoadSet(unsigned long ulBase, unsigned long ulTimer,
             unsigned long ulValue)
{
    //
    // Check the arguments.
    //
    ASSERT(TimerBaseValid(ulBase));
    ASSERT((ulTimer == TIMER_A) || (ulTimer == TIMER_B) ||
           (ulTimer == TIMER_BOTH));

    //
    // Set the timer A load value if requested.
    //
    if(ulTimer & TIMER_A)
    {
        HWREG(ulBase + TIMER_O_TAILR) = ulValue;
    }

    //
    // Set the timer B load value if requested.
    //
    if(ulTimer & TIMER_B)
    {
        HWREG(ulBase + TIMER_O_TBILR) = ulValue;
    }
}

//*****************************************************************************
//
//! Gets the timer load value.
//!
//! \param ulBase is the base address of the timer module.
//! \param ulTimer specifies the timer; must be one of \b TIMER_A or
//! \b TIMER_B.  Only \b TIMER_A should be used when the timer is configured
//! for 32-bit operation.
//!
//! This function gets the currently programmed interval load value for the
//! specified timer.
//!
//! \return Returns the load value for the timer.
//
//*****************************************************************************
unsigned long
TimerLoadGet(unsigned long ulBase, unsigned long ulTimer)
{
    //
    // Check the arguments.
    //
    ASSERT(TimerBaseValid(ulBase));
    ASSERT((ulTimer == TIMER_A) || (ulTimer == TIMER_B));

    //
    // Return the appropriate load value.
    //
    return((ulTimer == TIMER_A) ? HWREG(ulBase + TIMER_O_TAILR) :
           HWREG(ulBase + TIMER_O_TBILR));
}

//*****************************************************************************
//
//! Gets the current timer value.
//!
//! \param ulBase is the base address of the timer module.
//! \param ulTimer specifies the timer; must be one of \b TIMER_A or
//! \b TIMER_B.  Only \b TIMER_A should be used when the timer is configured
//! for 32-bit operation.
//!
//! This function reads the current value of the specified timer.
//!
//! \return Returns the current value of the timer.
//
//*****************************************************************************
unsigned long
TimerValueGet(unsigned long ulBase, unsigned long ulTimer)
{
    //
    // Check the arguments.
    //
    ASSERT(TimerBaseValid(ulBase));
    ASSERT((ulTimer == TIMER_A) || (ulTimer == TIMER_B));

    //
    // Return the appropriate timer value.
    //
    return((ulTimer == TIMER_A) ? HWREG(ulBase + TIMER_O_TAR) :
           HWREG(ulBase + TIMER_O_TBR));
}

//*****************************************************************************
//
//! Sets the timer match value.
//!
//! \param ulBase is the base address of the timer module.
//! \param ulTimer specifies the timer(s) to adjust; must be one of \b TIMER_A,
//! \b TIMER_B, or \b TIMER_BOTH.  Only \b TIMER_A should be used when the
//! timer is configured for 32-bit operation.
//! \param ulValue is the match value.
//!
//! This function sets the match value for a timer.  This is used in capture
//! count mode to determine when to interrupt the processor and in PWM mode to
//! determine the duty cycle of the output signal.
//!
//! \return None.
//
//*****************************************************************************
void
TimerMatchSet(unsigned long ulBase, unsigned long ulTimer,
              unsigned long ulValue)
{
    //
    // Check the arguments.
    //
    ASSERT(TimerBaseValid(ulBase));
    ASSERT((ulTimer == TIMER_A) || (ulTimer == TIMER_B) ||
           (ulTimer == TIMER_BOTH));

    //
    // Set the timer A match value if requested.
    //
    if(ulTimer & TIMER_A)
    {
        HWREG(ulBase + TIMER_O_TAMATCHR) = ulValue;
    }

    //
    // Set the timer B match value if requested.
    //
    if(ulTimer & TIMER_B)
    {
        HWREG(ulBase + TIMER_O_TBMATCHR) = ulValue;
    }
}

//*****************************************************************************
//
//! Gets the timer match value.
//!
//! \param ulBase is the base address of the timer module.
//! \param ulTimer specifies the timer; must be one of \b TIMER_A or
//! \b TIMER_B.  Only \b TIMER_A should be used when the timer is configured
//! for 32-bit operation.
//!
//! This function gets the match value for the specified timer.
//!
//! \return Returns the match value for the timer.
//
//*****************************************************************************
unsigned long
TimerMatchGet(unsigned long ulBase, unsigned long ulTimer)
{
    //
    // Check the arguments.
    //
    ASSERT(TimerBaseValid(ulBase));
    ASSERT((ulTimer == TIMER_A) || (ulTimer == TIMER_B));

    //
    // Return the appropriate match value.
    //
    return((ulTimer == TIMER_A) ? HWREG(ulBase + TIMER_O_TAMATCHR) :
           HWREG(ulBase + TIMER_O_TBMATCHR));
}

//*****************************************************************************
//
//! Registers an interrupt handler for the timer interrupt.
//!
//! \param ulBase is the base address of the timer module.
//! \param ulTimer specifies the timer(s); must be one of \b TIMER_A,
//! \b TIMER_B, or \b TIMER_BOTH.
//! \param pfnHandler is a pointer to the function to be called when the timer
//! interrupt occurs.
//!
//! This sets the handler to be called when a timer interrupt occurs.  This
//! will enable the global interrupt in the interrupt controller; specific
//! timer interrupts must be enabled via TimerIntEnable().  It is the interrupt
//! handler's responsibility to clear the interrupt source via TimerIntClear().
//!
//! \sa IntRegister() for important information about registering interrupt
//! handlers.