//P4.7－－－SDA
//P4.6－－－SCL
#include "msp430x43x.h"
#define V80   0X01;
#define HOLD  0X02;
#define W     0X04;
#define STE   0X01;
#define SI    0X02;
#define SO    0X04;
#define UCLK  0X08;
#define Ram_addr 0x250;
#define uchar unsigned char
#define uint unsigned int


void SpiWrite(char *Bufer,int cnt);
void SpiRead(int cnt);
void ReadID(void);
uchar  RXBufer[5];

void SpiWrite(char *Bufer,int cnt){ //Bufer是寫入的字符串，cnt是字符串的長度
  char data;
  int i,j;
  for(j=0;j<cnt;j++){
    data=Bufer[j];
    for(i=0;i<8;i++){
      P3OUT &= ~UCLK;      //SCK下降沿
      if(data&BIT7){        //高位是1;
        P3OUT |= SI;
      }       //主機輸出1
      else{
        P3OUT &= ~SI;
      }      //主機輸出0
      P3OUT |= UCLK;       //SCK上升沿
      data<<=1;
    }
  }
}
void SpiRead(int cnt){ //cnt是讀入數據的個數，讀入數據在RxBufrer[]中
  char data;
  int i,j;
  for(j=0;j<cnt;j++){
    for(i=0;i<8;i++){
      P3OUT &= ~UCLK;      //SCK下降沿
      if(P3IN&BIT2){
        data<<=1;
        data =data+BIT0;
      }
      else{
        data<<=1;
      }
      P3OUT |= UCLK;       //SCK上升沿
    }
    RXBufer[j] = data;
  }
}

void ReadID(void){ //read device’S ID;
  //int i;
  char command[4]={0xAB,0x00,0x00,0x01};     //0xAB是sst25P80的讀ID指令 
  P3OUT &= ~STE;                             //選中芯片
  SpiWrite(command,4);                       //給flash芯片發指令
  SpiRead(1);                                //讀取5個字符
  P3OUT |= STE;                              //CE拉高
}

void main(void)
{
  P1DIR |= 0x07;
  P3DIR |= 0x0B;
  P3DIR &= ~SO;                              //430的SO腳置為輸入模式            
  P1OUT |= V80;                              //芯片供電
  P3OUT &= ~STE;                             //選中芯片
  P1OUT |= W;                                //芯片非寫保護
  P1OUT |= HOLD;                             //芯片非hold模式
  P3OUT |= UCLK;                             //時鐘線先置高
  //P4OUT |= 0x08; 
  WDTCTL = WDTHOLD+WDTPW;
  ReadID();
  while(1);  
}