[牛人杂谈] M051的嵌套向量中断控制器 (NVIC)

/** \brief  Enable External Interrupt



    The function enables a device-specific interrupt in the NVIC interrupt controller.



    \param [in]      IRQn  External interrupt number. Value cannot be negative.

 */

__STATIC_INLINE void NVIC_EnableIRQ(IRQn_Type IRQn)

{

  NVIC->ISER[0] = (1 << ((uint32_t)(IRQn) & 0x1F));

}





/** \brief  Disable External Interrupt



    The function disables a device-specific interrupt in the NVIC interrupt controller.



    \param [in]      IRQn  External interrupt number. Value cannot be negative.

 */

__STATIC_INLINE void NVIC_DisableIRQ(IRQn_Type IRQn)

{

  NVIC->ICER[0] = (1 << ((uint32_t)(IRQn) & 0x1F));

}





/** \brief  Get Pending Interrupt



    The function reads the pending register in the NVIC and returns the pending bit

    for the specified interrupt.



    \param [in]      IRQn  Interrupt number.



    \return             0  Interrupt status is not pending.

    \return             1  Interrupt status is pending.

 */

__STATIC_INLINE uint32_t NVIC_GetPendingIRQ(IRQn_Type IRQn)

{

  return((uint32_t) ((NVIC->ISPR[0] & (1 << ((uint32_t)(IRQn) & 0x1F)))?1:0));

}





/** \brief  Set Pending Interrupt



    The function sets the pending bit of an external interrupt.



    \param [in]      IRQn  Interrupt number. Value cannot be negative.

 */

__STATIC_INLINE void NVIC_SetPendingIRQ(IRQn_Type IRQn)

{

  NVIC->ISPR[0] = (1 << ((uint32_t)(IRQn) & 0x1F));

}





/** \brief  Clear Pending Interrupt



    The function clears the pending bit of an external interrupt.



    \param [in]      IRQn  External interrupt number. Value cannot be negative.

 */

__STATIC_INLINE void NVIC_ClearPendingIRQ(IRQn_Type IRQn)

{

  NVIC->ICPR[0] = (1 << ((uint32_t)(IRQn) & 0x1F)); /* Clear pending interrupt */

}





/** \brief  Set Interrupt Priority



    The function sets the priority of an interrupt.



    \note The priority cannot be set for every core interrupt.



    \param [in]      IRQn  Interrupt number.

    \param [in]  priority  Priority to set.

 */

__STATIC_INLINE void NVIC_SetPriority(IRQn_Type IRQn, uint32_t priority)

{

  if(IRQn < 0) {

    SCB->SHP[_SHP_IDX(IRQn)] = (SCB->SHP[_SHP_IDX(IRQn)] & ~(0xFF << _BIT_SHIFT(IRQn))) |

        (((priority << (8 - __NVIC_PRIO_BITS)) & 0xFF) << _BIT_SHIFT(IRQn)); }

  else {

    NVIC->IP[_IP_IDX(IRQn)] = (NVIC->IP[_IP_IDX(IRQn)] & ~(0xFF << _BIT_SHIFT(IRQn))) |

        (((priority << (8 - __NVIC_PRIO_BITS)) & 0xFF) << _BIT_SHIFT(IRQn)); }

}





/** \brief  Get Interrupt Priority



    The function reads the priority of an interrupt. The interrupt

    number can be positive to specify an external (device specific)

    interrupt, or negative to specify an internal (core) interrupt.





    \param [in]   IRQn  Interrupt number.

    \return             Interrupt Priority. Value is aligned automatically to the implemented

                        priority bits of the microcontroller.

 */

__STATIC_INLINE uint32_t NVIC_GetPriority(IRQn_Type IRQn)

{



  if(IRQn < 0) {

    return((uint32_t)((SCB->SHP[_SHP_IDX(IRQn)] >> _BIT_SHIFT(IRQn) ) >> (8 - __NVIC_PRIO_BITS)));  } /* get priority for Cortex-M0 system interrupts */

  else {

    return((uint32_t)((NVIC->IP[ _IP_IDX(IRQn)] >> _BIT_SHIFT(IRQn) ) >> (8 - __NVIC_PRIO_BITS)));  } /* get priority for device specific interrupts  */

}





/** \brief  System Reset



    The function initiates a system reset request to reset the MCU.

 */

__STATIC_INLINE void NVIC_SystemReset(void)

{

  __DSB();                                                     /* Ensure all outstanding memory accesses included

                                                                  buffered write are completed before reset */

  SCB->AIRCR  = ((0x5FA << SCB_AIRCR_VECTKEY_Pos)      |

                 SCB_AIRCR_SYSRESETREQ_Msk);

  __DSB();                                                     /* Ensure completion of memory access */

  while(1);                                                    /* wait until reset */

}