학습목표    1

학습주제    1

예습내용    1

실습방법    1

        1

외부인터럽트 처리

학습목표

외부 인터럽트를 처리하는 방법을 배운다.

학습주제

“C언어에서 사용한 실습용보드를 사용해서 (INT0/SCL)PD0 스위치를 누를 마다 C포트의 Led 1회전 순차 점등하는 프로그램을 만든다.

예습내용

C언어의 함수 참조

실습방법

   

새로운 프로젝트에서 아래와 같이 외부인터럽트를 설정한다.

 

보기1  PD0 스위치를 누르면 8개의 Led 순차 점등 한다.

#include <mega128.h>

#include <delay.h>

 

// External Interrupt 0 service routine

interrupt [EXT_INT0] void ext_int0_isr(void)

{

// Place your code here

              char i,a=0x01; 

              for(i=0;i<9;i++) {

                             PORTC = ~a;

                             a=a<<1;

                             delay_ms(100);         

              }

}

 

// Declare your global variables here

 

void main(void)

{

// Declare your local variables here

 

// Input/Output Ports initialization

// Port A initialization

// Func0=In Func1=In Func2=In Func3=In Func4=In Func5=In Func6=In Func7=In

// State0=T State1=T State2=T State3=T State4=T State5=T State6=T State7=T

PORTA=0x00;

DDRA=0x00;

 

// Port B initialization

// Func0=In Func1=In Func2=In Func3=In Func4=In Func5=In Func6=In Func7=In

// State0=T State1=T State2=T State3=T State4=T State5=T State6=T State7=T

PORTB=0x00;

DDRB=0x00;

 

// Port C initialization

// Func0=Out Func1=Out Func2=Out Func3=Out Func4=Out Func5=Out Func6=Out Func7=Out

// State0=0 State1=0 State2=0 State3=0 State4=0 State5=0 State6=0 State7=0

PORTC=0x00;

DDRC=0xFF;

 

// Port D initialization

// Func0=In Func1=In Func2=In Func3=In Func4=In Func5=In Func6=In Func7=In

// State0=T State1=T State2=T State3=T State4=T State5=T State6=T State7=T

PORTD=0x00;

DDRD=0x00;

 

// Port E initialization

// Func0=In Func1=In Func2=In Func3=In Func4=In Func5=In Func6=In Func7=In

// State0=T State1=T State2=T State3=T State4=T State5=T State6=T State7=T

PORTE=0x00;

DDRE=0x00;

 

// Port F initialization

// Func0=In Func1=In Func2=In Func3=In Func4=In Func5=In Func6=In Func7=In

// State0=T State1=T State2=T State3=T State4=T State5=T State6=T State7=T

PORTF=0x00;

DDRF=0x00;

 

// Port G initialization

// Func0=In Func1=In Func2=In Func3=In Func4=In

// State0=T State1=T State2=T State3=T State4=T

PORTG=0x00;

DDRG=0x00;

 

// Timer/Counter 0 initialization

// Clock source: System Clock

// Clock value: Timer 0 Stopped

// Mode: Normal top=FFh

// OC0 output: Disconnected

TCCR0=0x00;

ASSR=0x00;

TCNT0=0x00;

OCR0=0x00;

 

// Timer/Counter 1 initialization

// Clock source: System Clock

// Clock value: Timer 1 Stopped

// Mode: Normal top=FFFFh

// OC1A output: Discon.

// OC1B output: Discon.

// OC1C output: Discon.

// Noise Canceler: Off

// Input Capture on Falling Edge

TCCR1A=0x00;

TCCR1B=0x00;

TCNT1H=0x00;

TCNT1L=0x00;

OCR1AH=0x00;

OCR1AL=0x00;

OCR1BH=0x00;

OCR1BL=0x00;

OCR1CH=0x00;

OCR1CL=0x00;

 

// Timer/Counter 2 initialization

// Clock source: System Clock

// Clock value: Timer 2 Stopped

// Mode: Normal top=FFh

// OC2 output: Disconnected

TCCR2=0x00;

ASSR=0x00;

TCNT2=0x00;

OCR2=0x00;

 

// Timer/Counter 3 initialization

// Clock source: System Clock

// Clock value: Timer 3 Stopped

// Mode: Normal top=FFFFh

// OC3A output: Discon.

// OC3B output: Discon.

// OC3C output: Discon.

TCCR3A=0x00;

TCCR3B=0x00;

TCNT3H=0x00;

TCNT3L=0x00;

OCR3AH=0x00;

OCR3AL=0x00;

OCR3BH=0x00;

OCR3BL=0x00;

OCR3CH=0x00;

OCR3CL=0x00;

 

// External Interrupt(s) initialization

// INT0: On

// INT0 Mode: Rising Edge

// INT1: Off

// INT2: Off

// INT3: Off

// INT4: Off

// INT5: Off

// INT6: Off

// INT7: Off

EICRA=0x03;

EICRB=0x00;

EIMSK=0x01;

EIFR=0x01;

 

// Timer(s)/Counter(s) Interrupt(s) initialization

TIMSK=0x00;

ETIMSK=0x00;

 

// Analog Comparator initialization

// Analog Comparator: Off

// Analog Comparator Input Capture by Timer/Counter 1: Off

// Analog Comparator Output: Off

ACSR=0x80;

SFIOR=0x00;

 

// Global enable interrupts

#asm("sei")

 

while (1)

      {

      // Place your code here

 

      };

}

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