Nested Vectored Interrupt Controller (NVIC)
包含在Cortex-M4F 中，
优先级有16级
中断相关寄存器
ISER[0-3]:Interrupt Set Enable Register
ICER[0-3]:Interrupt Clear Enable Register
ISPR[0-3]:Interrupt Set Pending Register
ICPR[0-3]:Interrupt Clear Pending Register
IABR[0-3]:Interrupt Active bit Register
IP[0-122]:Interrupt Priority Register
STIR:Software Trigger Interrupt Register
以外部中断PORTC_IRQn 为例
查看S32K1xx_DMA_INT_mapping.xlsm
屏幕剪辑的捕获时间: 2019/8/4 6:59
第三列 NVIC Interrupt ID 表示中断号
第四列 ISER, ICER, ISPR, ICPR, and IABR 寄存器号，等于NVIC Interrupt ID 整除32
第五列 IPR寄存器号 *实际为每个寄存器存4个中断源优先级，程序已经分开定义成了0-122 直接IPR[NVIC interrupt ID]即可
初始化时在应用模块配置好后（如外部中断需要在PCR中配置IRQC），加下以下NVIC 配置
S32_NVIC->ICPR[PORTC_IRQn/32] = 1 << (PORTC_IRQn % 32); /* clr any pending IRQ*/
S32_NVIC->ISER[PORTC_IRQn/32] = 1 << (PORTC_IRQn % 32); /* enable IRQ */
S32_NVIC->IP[PORTC_IRQn] = 0xA0; /* priority 10 of 0-15*/
中断程序写对应用.s 里中断指向的程序
void PORTC_IRQHandler (void) {
PORTC->ISFR=0xFFFFFFFFu;/* Clear button IRQ flag */
}
完整程序：
#include "S32K144.h" /* include peripheral declarations S32K144 */
#define PTD0 0 /* Port PTD0, bit 0: FRDM EVB output to blue LED */
#define PTC12 12 /* Port PTC12, bit 12: FRDM EVB input from BTN0 [SW2] */
void PORTC_IRQHandler (void) {
PORTC->ISFR=0xFFFFFFFFu;
/* Perform read-after-write to ensure flag clears before ISR exit */
PTD->PTOR |= 1<<0; /* Toggle output on port D0 (blue LED) */
}
int main(void) {
/* Enable clocks to peripherals (PORT modules) */
PCC-> PCCn[PCC_PORTC_INDEX] = PCC_PCCn_CGC_MASK; /* Enable clock to PORT C */
PCC-> PCCn[PCC_PORTD_INDEX] = PCC_PCCn_CGC_MASK; /* Enable clock to PORT D */
/* Configure port C12 as GPIO input (BTN 0 [SW2] on EVB) */
PORTC->DFCR=1; //Digital Filter Clock=LPO
PORTC->DFWR=8; //Digital Filter width=8
PORTC->DFER=1<<PTC12; //Enable Digital Filter
PTC->PDDR &= ~(1<<PTC12); /* Port C12: Data Direction= input (default) */
PORTC->PCR[12] = 0x00090110; /* Port C12: MUX = GPIO, input filter enabled，Interrupt on rising edge */
S32_NVIC->ICPR[PORTC_IRQn/32] = 1 << (PORTC_IRQn % 32); /* clr any pending IRQ*/
S32_NVIC->ISER[PORTC_IRQn/32] = 1 << (PORTC_IRQn % 32); /* enable IRQ */
S32_NVIC->IP[PORTC_IRQn] = 0xA0; /* priority 10 of 0-15*/
/* Configure port D0 as GPIO output (LED on EVB) */
PTD->PDDR |= 1<<PTD0; /* Port D0: Data Direction= output */
PORTD->PCR[0] = 0x00000100; /* Port D0: MUX = GPIO */
for(;;) {
}
}