根据AVR单片机I/O演示C言语程序

//程序流程:全亮->全灭->PD隔一步进->全亮->全灭->PD隔二步进->全亮->全灭->PB全亮->pb0置位->pb0清零->PB0回转->全灭->（循环）

// Target : M8
// Crystal: 11.059Mhz

#include
#include

//开始全亮
void port_init(void)
{
PORTB = 0x00;
DDRB = 0xFF;
PORTC = 0x00;
DDRC = 0x7F;
PORTD = 0x00;
DDRD = 0xFF;
}

//延时函数，大约1ms；
void delay(char tim)
{
unsigned int i,j;
for(i=0;i for(j=0;j<10000;j++);
}

//led全亮
void led_on(void)
{
PORTB = 0x00;
PORTC = 0x00;
PORTD = 0x00;

delay(5000);
}
//led全灭
void led_off(void)
{
PORTB = 0xFF;
PORTC = 0xFF;
PORTD = 0xFF;

delay(5000);
}
//PB隔1步进
void pd_1(void)
{
char i;
for (i = 0; i < 8; i++)
{
PORTB = ~(1 << (i));//位操作结合移位操作
delay(5000);
}
}
//PB隔2步进
void pd_2(void)
{
char i;
for (i = 0; i < 8; i+=2)
{
PORTB = ~(1 << (i));//位操作结合移位操作
delay(5000);
}
}

//call this routine to initialise all peripherals
void init_devices(void)
{
//stop errant interrupts until set up
CLI(); //disable all interrupts
port_init();

MCUCR = 0x00;
GICR = 0x00;
TIMSK = 0x00; //timer interrupt sources
SEI(); //re-enable interrupts
//all peripherals are now initialised
}

//
void main(void)
{
init_devices();

while(1)
{
led_on();
led_off();

led_on();
led_off();

pd_1();

led_on();
led_off();

pd_2();

led_on();
led_off();

//赋值(会给一切的位以特定值)，使pb0为0，led亮；
PORTB = 0xFE;
delay(5000);
//置位（不影响其他位），使pb0为1，led灭；
PORTB |= 0x01;
delay(5000);
//清零（不影响其他位），使pb0为0，led亮；
PORTB &= ~0x01;
delay(5000);
//回转（不影响其他位），使pb0为1，led灭；
PORTB ^= 0x01;
delay(5000);
}
}