芯片是S3C2440

首先看原理图，led_1234分别对应引脚GPB 5678

设置引脚为输出

向寄存器相应位写入

#define GPBCON (*(volatile unsigned long *)0x56000010)           //p5 6 7 8

void led_init(void)
{
    GPBCON &= ~(0x3 << 10);
    GPBCON |=  (0x1 << 10);

    GPBCON &= ~(0x3 << 12);
    GPBCON |=  (0x1 << 12);

    GPBCON &= ~(0x3 << 14);
    GPBCON |=  (0x1 << 14);

    GPBCON &= ~(0x3 << 16);
    GPBCON |=  (0x1 << 16);

}

查看手册描述

大意为我们在相应引脚赋1就是高电平，0就是低电平。学过51单片机的同学应该很熟悉。只不过这里用了寄存器。

void led_off(int led_num)
{
    led_num += 5;
    GPBDAT |= (0x1 << led_num);
}

led_on(int led_num)
{
    led_num += 5;
     GPBDAT &= ~(0x1 << led_num);
}

按键也是同理

#define GPBCON (*(volatile unsigned long *)0x56000010UL)           //p5 6 7 8
#define GPBDAT (*(volatile unsigned long *)0x56000014UL)

#define GPGCON (*(volatile unsigned long *)0x56000060UL)
#define GPGDAT (*(volatile unsigned long *)0x56000064UL)

void c_deal_swi(int num)
{
    switch (num)
    {
    case 5/* constant-expression */:
        /* code */
        break;
    
    default:
        break;
    }
}

//微秒级的延时
void delay_us(unsigned int delay_us)
{
  volatile unsigned int num;
  volatile unsigned int t;


  for (num = 0; num < delay_us; num++)
  {
    t = 11;
    while (t != 0)
    {
      t--;
    }
  }
}


void led_init(void)
{
    GPBCON &= ~(0x3 << 10);
    GPBCON |=  (0x1 << 10);

    GPBCON &= ~(0x3 << 12);
    GPBCON |=  (0x1 << 12);

    GPBCON &= ~(0x3 << 14);
    GPBCON |=  (0x1 << 14);

    GPBCON &= ~(0x3 << 16);
    GPBCON |=  (0x1 << 16);

    GPBDAT |= (0x1 << 5);   //初始设置灯灭
    GPBDAT |= (0x1 << 6);
    GPBDAT |= (0x1 << 7);
    GPBDAT |= (0x1 << 8);
}

void led_off(int led_num)
{
    led_num += 5;
    GPBDAT |= (0x1 << led_num);
}

led_on(int led_num)
{
    led_num += 5;
     GPBDAT &= ~(0x1 << led_num);
}


void led_start(void)
{
    int i = 0;
    for(i = 0; i < 4; ++i)
    {
        led_on(i);
		delay_us(1000);
    }
    
    
    for(i = 0; i < 4; ++i)
    {
        led_off(i);
		delay_us(1000);
    }
   
}

void key_init(void) //k0\k1    g5  g3
{
    GPGCON &= ~(0x3 << 5);
    GPGCON &= ~(0x1 << 5);

    GPGCON &= ~(0x3 << 3);
    GPGCON &= ~(0x1 << 3);
}

int key_find(int key_num)
{
    if(key_num == 1)
    {
        if((GPGDAT & ~(0x1 << 5)) == GPGDAT)
        {
            return 1;
        }
        return 0;        
    }
    else if(key_num == 2)
    {
        if((GPGDAT & ~(0x1 << 3)) == GPGDAT)
        {
            return 1;
        }
        return 0;        
    }
    
}

int main(void)
{
	int flag;
    if(key_find(1))
    {
		flag = 1;            
    }
    else if(key_find(2))
    {
		flag = 0;    
    }

	if(flag == 1)
	{	
		led_on(1);	
	}
	else if(flag == 0)
	{
		led_off(1);	
	}
}