main.c

DG128 SPI 接口程序 在飞思卡尔DG128完成SPI协议的通信

#include <hidef.h>      /* common defines and macros */
#include <mc9s12dg128.h>     /* derivative information */
#pragma LINK_INFO DERIVATIVE "mc9s12dg128b"

//写、读一个字节
U8 SPI_RdWr_Byte(U8 val)
{
	SPI0DR = val;
	while(!(SPI0SR_SPIF));
	return SPI0DR;
}
U8 SPI_ReadByte(void)
{
	SPI0DR = 0xff;
	while(!(SPI0SR_SPIF));
	return SPI0DR;
}
void SPI_Init(void) 
{
  DDRT = 0xff;
  MODRR   = 0x00;  
  SPI0CR2 = 0x10;
  SPI0CR1 = 0x5e;
  //SPI0BR  = 0x02; //BR=2M 
  SPI0BR  = 0x42; //BR=busclk/((SPPR + 1)· 2^(SPR + 1))=16000/(5*8)=400k                 
}
void setbusclock(void)
{   
    CLKSEL=0X00;				          //disengage PLL to system
    PLLCTL_PLLON=1;			          //turn on PLL
    SYNR=1;										
    REFDV=1;		                  //pllclock=2*osc*(1+SYNR)/(1+REFDV)=32MHz;
    _asm(nop);                    //If PLL is selected (PLLSEL=1), Bus Clock = PLLCLK / 2=16M     
    while(!(CRGFLG_LOCK==1)) 
      _asm(nop);	                //when pll is steady ,then use it;
    CLKSEL_PLLSEL =1;		          //engage PLL to system; 
}

void main(void) {
  /* put your own code here */
  EnableInterrupts;
  
  setbusclock();  
  SPI_Init();
  
  for(;;){
  
  
  } 
  
}