//參考程序A  :  SPI調(diào)試程序  :WSPILM74.c
//SPI調(diào)試程序  :WSPILM74.c
#include <C8051F020.h>	
#include <intrins.h>
#define PORTA		0x8000	       /*8255的A口*/
#define	PORTB		0x8001     /*8255的B口*/
#define	PORTC		0x8002     /*8255的C口*/
#define	PORTCON		0x8003     /*8255的控制口*/
typedef unsigned char uchar;
typedef unsigned int uint;
uint h;
uchar xdata  *idata Pointm;	
uchar HMS[6],rr[3],h1,h2,h3,h4,i,j,k0,k1;
uchar WE[6]={1,2,4,8,0x10,0x20};   //位選
uchar ZI[20]={0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f,0x77,
0x7c,0x39,0x5e,0x79,0x71,0x40};/*字選:0,1,2,3,4,5,6,7,8,9,a,b,c,d,e,f,-*/
void PORT_Init (void);
void displayled(void);
void delay1ms(uint time){//延遲1ms
	uint ii;
	uint jj;
	for (ii=0;ii<time;ii++){
		for(jj=0;jj<300;jj++);
	}
	}
exch();    //數(shù)據(jù)轉(zhuǎn)換
void PORT_Init ();
void spi_cfg(uchar spicfg,uchar spickr,uchar spicn)//SPI配置函數(shù)
{
	 SPI0CFG = spicfg;	//設(shè)定寄存器SPI0CFG=0C7H
	 SPI0CKR = spickr;	//設(shè)定寄存器SPI9CKR=27H
     SPI0CN = spicn;	//設(shè)定寄存器SPI0CN =03 
     EIE1|= 0x01;
}
void config (void)  //config function
{
    WDTCN = 0xDE;  	//看門狗禁止
    WDTCN = 0xAD;
	XBR0 = 0x02;/*交叉開關(guān)配置,SPI總線SCK配置到P0.0口，
	            MOSI為P0.2口， NSS為P0.3,MISO配置到P0.1口*/
	XBR1 = 0x00;	
	XBR2 = 0x40;   /*允許功能選擇開關(guān)有效*/
    P0MDOUT = 0x0D;/*SCK、MOSI和NSS為推拉式輸出，MISO為開漏式.*/
}  
void main()   //主程序
{
    PORT_Init ();
	config();
	spi_cfg(0x0C7,0x27,0x03);//設(shè)定寄存器SPI0CFG,SPI0CKR和SPI0CN 
	while(1)
	{
	P0=0xff;
	EA=1;
	i=0;
	P0&=0x7f;
	delay1ms(1);//延時(shí)
   SPI0DAT=0x00;
//當(dāng)對SPI0SAT寫數(shù)據(jù)時(shí)，產(chǎn)生時(shí)鐘信號,讀入從LM74發(fā)來的高8位數(shù)據(jù)
    delay1ms(2);
	SPI0DAT=0x00;
//當(dāng)對SPI0SAT寫數(shù)據(jù)時(shí)，產(chǎn)生時(shí)鐘信號,讀入從LM74發(fā)來的低8位數(shù)據(jù)
    delay1ms(2);
	if(i==2){	//已收到16位數(shù)據(jù),就將1-->/CS并轉(zhuǎn)入顯示溫度值的函數(shù).
	P0|=0x80;
	delay1ms(5);
    EA=0;        //關(guān)中斷
    exch();      //數(shù)據(jù)處理函數(shù)
    displayled();//顯示溫度值的函數(shù).
	};
    }
}
exch() //數(shù)據(jù)格式轉(zhuǎn)換,將二進(jìn)制轉(zhuǎn)換為十進(jìn)制.
{  HMS[0]=0;
 h=(256*rr[0]+rr[1])/128;//rr[0]中存放高8位數(shù),rr[1]中存放低8位數(shù)
if(h>=128)    //判別符號位
  {
  h=-h;      //若為負(fù)號,先求補(bǔ)碼 
  HMS[0]=0x10;//"-"號(字形碼:  40H)
  };
 
  h1=h/100;
  h2=(h-h1*100)/10;
  h3=(h-h1*100-h2*10);
  HMS[1]=h1;
  HMS[2]=h2;
  HMS[3]=h3;
  HMS[4]=0;
  h1=rr[1]&0x40;//判別0.5度
  if(h1!=0)
  HMS[4]=5;
  HMS[5]=0x0c;   //顯示"C"
  }

void spi_ISR() interrupt 6//SPI中斷
{  EA=0;
   while(TXBSY);	
    SPIF=0;
	rr[i]=SPI0DAT;//由于是全雙工總線，在發(fā)送完一個字節(jié)時(shí)，
	              //主機(jī)也收到從機(jī)所發(fā)的數(shù)據(jù)
	i++;
EA=1;
}
void PORT_Init (void)
{
   OSCICN=0x05   ;/*選擇內(nèi)部振蕩器，內(nèi)部振蕩器按IFCN指定的頻率運(yùn)行，
			                       ;頻率為8MHz*/
   OSCXCN = 0x67;	//外部為11.0592MHZ(未采用)	
   P74OUT  = 0x0ff;      /*P7為推拉方式,P4,P5,P6漏極開路*/
   EMI0CF |= 0x2c;		/*EMIF工作在地址/數(shù)據(jù)復(fù)用方式，只用外部存儲器，ALE高/低脈寬占1個SYSCLK周期*/
   EMI0TC |= 0x6d;		/*地址建立/保持時(shí)間占0個SYSCLK周期，/WR和/RD占12個SYSCLK周期*/
   Pointm=PORTCON;      /*8255初始化*/
   *Pointm=0x80;		
}
void displayled(void) //顯示六位溫度數(shù)據(jù):-020.5C
{unsigned  int  p;
unsigned  char  pp;
for(j=0;j<6;j++)
	    { 
			pp=(HMS[j]);	/*轉(zhuǎn)化成數(shù)碼管數(shù)字顯示碼*/
			k0=ZI[pp];        /*查表*/
			Pointm=PORTB;  	//動態(tài)驅(qū)動6數(shù)碼管
            k1=WE[j];       /*查表*/
			*Pointm=k1; 
			Pointm=PORTC; 
			*Pointm=k0+0x80;	/*加小數(shù)點(diǎn)*/
		if(k1!=8)
	    (*Pointm=k0);	/*送顯示碼*/
	    for(p=0;p<=1000;p++);
		_nop_();
		}
	}