90keyc.c

单片机开发资料光盘-双龙-686M.zip

/*                    Pc.4--cs
                      Pc.3--clk
                      Pc.2--data
                      Pc.1--key  */



#include<io8515.h>
#pragma ctask  receive()
/*delay()send() */

#define clrcs     PORTC&=~0x10;
#define setcs     PORTC|=0x10;
#define clrclk    PORTC&=~0x08;
#define setclk    PORTC|=0x08;
#define clrdata   PORTC&=~0x04;
#define setdata   PORTC|=0x04;
#define datainput {DDRC&=~0x04;PORTC&=~0x04;}
#define dataoutput{DDRC|=0x04; PORTC&=~0x04;}

unsigned char  send_buff,rec_buff,ms;

void delay(unsigned char mst)         //延时子程序
 {  unsigned char i;
     for (i = 1; i<mst; i++)
			;
 }


void send(unsigned char temp)    //发送子程序
{
 unsigned char i;
 clrcs
 delay(20);
 clrclk
 for(i=8;i>0;i--)
  {
   if((temp&0x80)==0)
    {
	clrdata
    } 
   else
    {
	setdata    
    }   
   setclk
   delay(4);
   clrclk
   delay(4);
   temp=temp<<1;
  }
 clrdata  
} 

void receive()                //接收子程序
{
 unsigned char i;
 datainput
 delay(20); 
 for(i=8;i>0;i--)
 { 
  rec_buff=rec_buff<<1;
  setclk
  delay(4);
  if((PINC&0x04)==0)
   {
    rec_buff=rec_buff&0xfe;
   }
   else
   {
	rec_buff|=rec_buff|0x01;	
   }
  clrclk
  delay(4);

 } 
 dataoutput	
} 

void  main()
{
 DDRC=0xfd;
 PORTC=0xf7;
 send(0xa4);
 setcs
wait:
 if((PINC&0x02)==2)             //是否有按键 
  {
   goto wait;                   //否，等待按键
  }
 send(0x15);                      
 receive();
 setcs
 send(0xc8);
 send(rec_buff);
 setcs
wait1:
 if((PINC&0x02)==0)             //是否有松键
  {

   goto wait1;                  //否，等待松键
  }
 goto wait;                     //返回
}