CH32V003_nesting_priority_interrupt

#include "ch32v00x.h"

volatile uint32_t cnt = 0;
uint32_t result;

//#define  NESTING

#ifdef NESTING

void __attribute__((interrupt("WCH-Interrupt-fast"))) SW_Handler(void){  // #14

    cnt++;

    EXTI->INTENR |= EXTI_INTENR_MR0;
    EXTI->SWIEVR |= EXTI_SWIEVR_SWIEVR0;
    while(1){
         if(!(EXTI->SWIEVR & EXTI_SWIEVR_SWIEVR0))
             EXTI->SWIEVR |= EXTI_SWIEVR_SWIEVR0;
      }
}

void __attribute__((interrupt("WCH-Interrupt-fast"))) EXTI7_0_IRQHandler(void){ // #20

   EXTI->INTFR = EXTI_INTF_INTF0;

}

void main(void){

  __asm volatile("csrr %0,0x804" : "=r"(result)); // что в настройках стартапа?

  NVIC_SetPriority(Software_IRQn, 0b10 << 6); //#14  IPRIOR14 [7:6] <- 0x10
  NVIC_SetPriority(EXTI7_0_IRQn,  0b00 << 6); //#20  IPRIOR20 [7:6] <- 0x01

  NVIC_EnableIRQ(Software_IRQn);
  NVIC_EnableIRQ(EXTI7_0_IRQn);

  SysTick->CTLR |= (uint32_t)(1 << 0);    // вкл SysTick
  SysTick->CTLR |= (uint32_t)(1 << 31);   // вкл SWI

  while(1);
}

#else

void __attribute__((interrupt("WCH-Interrupt-fast"))) SW_Handler(void){  // #14

    cnt++;

}

void __attribute__((interrupt("WCH-Interrupt-fast"))) EXTI7_0_IRQHandler(void){ // #20

   EXTI->INTFR = EXTI_INTF_INTF0;

}

void main(void){

  __asm volatile("csrr %0,0x804" : "=r"(result));                 // чтение
  __asm volatile("fence");
  __asm volatile("csrrw %0, 0x804, %1" : "=r"(result) :"r"(0x1)); //чтение - запись
  __asm volatile("csrr %0,0x804" : "=r"(result));                 // что теперь в настройках?

  __disable_irq();


  EXTI->INTENR |= EXTI_INTENR_MR0;
  EXTI->SWIEVR |= EXTI_SWIEVR_SWIEVR0;

  SysTick->CTLR |= (uint32_t)(1 << 0);    // вкл SysTick
  SysTick->CTLR |= (uint32_t)(1 << 31);   // вкл SWI

  NVIC_SetPriority(Software_IRQn, 0b10 << 6); //#14  IPRIOR14 [7:6] <- 0x10
  NVIC_SetPriority(EXTI7_0_IRQn,  0b01 << 6); //#20  IPRIOR20 [7:6] <- 0x01

  NVIC_EnableIRQ(Software_IRQn);
  NVIC_EnableIRQ(EXTI7_0_IRQn);

  __enable_irq();

  while(1);
}

#endif