Cortex-M0 LPC1114中断优先级怎么设置

LPC1114的中断，由中断控制模块NVIC控制。一共32个中断，每个中断的优先级可编程为 0~3 四种级别。级别越高对应的优先级越低。因此，级别0 是最高的中断优先级。

设置中断优先级的函数，CMISIS已经写好，并嵌入到了编译器中，例如，我们用KEIL开发的话，设置中断优先级的函数位于core_cm0.h文件当中，函数如下所示：

/** \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)
{
　　) {
　　　　SCB->SHP[_SHP_IDX(IRQn)] = (SCB->SHP[_SHP_IDX(IRQn)] & ~(0xFF << _BIT_SHIFT(IRQn))) |
　　　　(((priority << ( - __NVIC_PRIO_BITS)) & 0xFF) << _BIT_SHIFT(IRQn)); }
　　else {
　　　　NVIC->IP[_IP_IDX(IRQn)] = (NVIC->IP[_IP_IDX(IRQn)] & ~(0xFF << _BIT_SHIFT(IRQn))) |
　　　　(((priority << ( - __NVIC_PRIO_BITS)) & 0xFF) << _BIT_SHIFT(IRQn)); }
}

　　从上面函数可以看出，该函数有两个参数，IRQn是指你要设置的中断向量，priority是中断优先级，优先级可以是0 1 2 3四个数，0的优先级最大，3的优先级最小。假设你要设置GPIO1中断的优先级最高，那么就是：

NVIC_SetPriority(EINT1_IRQn, 0);

　　这时，有人会问，”EINT1_IRQn”从哪里来？答：这个可以在LPC11xx.h文件当中找到，如下所示：

/*
* ==========================================================================
* ---------- Interrupt Number Definition -----------------------------------
* ==========================================================================
*/
typedef enum IRQn
{
/****** Cortex-M0 Processor Exceptions Numbers ***************************************************/
Reset_IRQn = -, /*!< 1 Reset Vector, invoked on Power up and warm reset */
NonMaskableInt_IRQn = -, /*!< 2 Non maskable Interrupt, cannot be stopped or preempted */
HardFault_IRQn = -, /*!< 3 Hard Fault, all classes of Fault */
SVCall_IRQn = -, /*!< 11 System Service Call via SVC instruction */
PendSV_IRQn = -, /*!< 14 Pendable request for system service */
SysTick_IRQn = -, /*!< 15 System Tick Timer */

/****** LPC11Cxx or LPC11xx Specific Interrupt Numbers *******************************************************/
WAKEUP0_IRQn = , /*!< All I/O pins can be used as wakeup source. */
WAKEUP1_IRQn = , /*!< There are 13 pins in total for LPC11xx */
WAKEUP2_IRQn = ,
WAKEUP3_IRQn = ,
WAKEUP4_IRQn = ,
WAKEUP5_IRQn = ,
WAKEUP6_IRQn = ,
WAKEUP7_IRQn = ,
WAKEUP8_IRQn = ,
WAKEUP9_IRQn = ,
WAKEUP10_IRQn = ,
WAKEUP11_IRQn = ,
WAKEUP12_IRQn = ,
CAN_IRQn = , /*!< CAN Interrupt */
SSP1_IRQn = , /*!< SSP1 Interrupt */
I2C_IRQn = , /*!< I2C Interrupt */
TIMER_16_0_IRQn = , /*!< 16-bit Timer0 Interrupt */
TIMER_16_1_IRQn = , /*!< 16-bit Timer1 Interrupt */
TIMER_32_0_IRQn = , /*!< 32-bit Timer0 Interrupt */
TIMER_32_1_IRQn = , /*!< 32-bit Timer1 Interrupt */
SSP0_IRQn = , /*!< SSP0 Interrupt */
UART_IRQn = , /*!< UART Interrupt */
Reserved0_IRQn = , /*!< Reserved Interrupt */
Reserved1_IRQn = ,
ADC_IRQn = , /*!< A/D Converter Interrupt */
WDT_IRQn = , /*!< Watchdog timer Interrupt */
BOD_IRQn = , /*!< Brown Out Detect(BOD) Interrupt */
FMC_IRQn = , /*!< Flash Memory Controller Interrupt */
EINT3_IRQn = , /*!< External Interrupt 3 Interrupt */
EINT2_IRQn = , /*!< External Interrupt 2 Interrupt */
EINT1_IRQn = , /*!< External Interrupt 1 Interrupt */
EINT0_IRQn = , /*!< External Interrupt 0 Interrupt */
} IRQn_Type;