iar14-2slave.c

手把手教你学AVR单片机C程序设计实验程序

#include<iom16.h>
#define uchar unsigned char	//变量类型的宏定义
#define uint  unsigned int	
#define CLR_BIT(x,y) (x&=~(1<<y))
#define SPIF 7
#define xtal 8
uchar __flash SEG7[10]={0x3f,0x06,0x5b,0x4f,0x66,	
                0x6d,0x7d,0x07,0x7f,0x6f};
uchar __flash ACT[8]={0xfe,0xfd,0xfb,0xf7,0xef,0xdf,0xbf,0x7f};	
uchar RXbuffer[10];
uchar i=0;
/**********************************/
void Delay_1ms(void)		
{ uint i;
 for(i=1;i<(uint)(xtal*143-2);i++)
    ;
}
//=============================================
void Delay_nms(uint n)		
{
 uint i=0;
   while(i<n)
   {
    Delay_1ms();
    i++;
   }
}
/*******************************/
void port_init(void)
{
 PORTA = 0x00; 
 DDRA  = 0xFF;
 PORTC = 0xFF; 
 DDRC  = 0xFF; 
 PORTB = 0x10; 
 DDRB  = 0x40;
}
/*******************************/
void spi_init(void)
{
 SPCR = 0x41; //setup SPI
}
/*******************************/
uchar SPI_slavereceive(void)
{
 while(!(SPSR&(1<<SPIF))) ;
 CLR_BIT(SPSR,SPIF);
 return SPDR;
}
/*********************************************/
void main(void)
{
  Delay_nms(50);	
  port_init();
  spi_init();
  SPDR=0x55;
  while(1)
  { 
    RXbuffer[i]=SPI_slavereceive();
    SPDR=0x55;
    PORTA = SEG7[RXbuffer[i]]; 
    PORTC = ACT[0];
    if(++i>9)i=0;
  }
}