ADS LED ON/OFF(PIT) 김진철

< LED.h>

#ifndef _LED_H_

#define _LED_H_

#include "AT91SAM7S256.h"

#define LED_PIN AT91C_PIO_PA0 // LED PIN을 0을 사용

#define __ON__ 1

#define __OFF__ 0

#define PICNT 20

void LED_Init(void);

void LED_On(void);

void LED_Off(void);

unsigned int LED_State(void);

void LED_Toggle(void);

#endif //_LED_H_

<led.c>

#include "LED.h"

static volatile unsigned int uiState; // 접근 금지

void LED_Init(void)

{

*AT91C_PMC_PCER = (1<<AT91C_ID_PIOA); // 전원 공급

*AT91C_PIOA_PER = LED_PIN;

*AT91C_PIOA_OER = LED_PIN;

*AT91C_PIOA_PPUDR = LED_PIN;

*AT91C_PIOA_SODR = LED_PIN; // LED OFF

uiState = __OFF__;

}

void LED_On(void)

{

*AT91C_PIOA_CODR = LED_PIN; // LED ON

uiState = __ON__;

}

void LED_Off(void)

{

*AT91C_PIOA_SODR = LED_PIN; // LED OFF

uiState = __OFF__;

}

unsigned int LED_State(void)

{

return uiState;

}

void LED_Toggle(void)

{

volatile unsigned int iCnt;

if(uiState == __OFF__)

{

LED_On();

uiState = __ON__;

}

else

{

LED_Off();

uiState = __OFF__;

}

}

< main.c>

#include "AT91SAM7S256.h"

#include "LED.h"

void PIT_Init(void);

void ISR_System(void);

//volatile unsigned int iCnt;

int main(void)

{

LED_Init();

PIT_Init();

while (1)

{

}

return 0;

}

void PIT_Init(void)

{

AT91C_AIC_SVR[AT91C_ID_SYS] = (unsigned int)ISR_System;

*AT91C_AIC_IECR = (1<<AT91C_ID_SYS);

*AT91C_PITC_PIMR = AT91C_PITC_PITEN |  AT91C_PITC_PITIEN | 0xF4240; // 0.3333초 마다 인터럽트(1/3초)

}

void ISR_System(void)

{

static unsigned int i;

/*

static unsigned int iCnt;

++iCnt;

if(0 == (iCnt%3))

{

LED_Toggle();

}

*/

if(0 != *AT91C_PITC_PISR)

{

if(1==(*AT91C_PITC_PIVR >> PICNT)) //AT91C_PITC_PIVR 상태를 읽어드릴때 초기화

{

++i;

if((i%3) == 0)

{

LED_Toggle();

}

}

}

}