讨论XS串口问题

chuxinggz · 发表于 2009-9-27 16:47:11

这个程序为什么不能正确收发数据啊？请大家帮我看看

#include <hidef.h>    /* common defines and macros */
#include <MC9S12XS128.h>    /* derivative information */
#pragma LINK_INFO DERIVATIVE "mc9s12xs128"
#include "main_asm.h" /* interface to the assembly module */

#define uchar unsigned char
#define uint unsigned int

uchar R_date,R_flag;
uchar T_date,T_flag;
uint numeric;
void PLL(void);
void SCI_INIT(void);
void NORMAL_IO_INIT(void);
uchar SCI_R(void);
void delay(uint z);
void SCI_T(uchar T_date);

void SCI_INIT(void)
{
SCI0BD=312.5;
SCI0CR1=0X00;
SCI0CR2=0B00001100;
SCI0CR2_RIE = 1;
SCI0CR2_TIE = 1;
}
void PLL(void)//48MHz
{
  CLKSEL=0X00;
  PLLCTL_PLLON =1;
  SYNR = 0xC0|0X05;
  REFDV= 0xC0|0x01;  // PLLCLK =2*OSCCLK*(SYNR + 1)/(REFDV + 1)
  POSTDIV=0X00;
  _asm(nop);
  _asm(nop);
  while(CRGFLG_LOCK == 0);
  CLKSEL_PLLSEL = 1;
}
void NORMAL_IO_INIT()
{
DDRB=0XFF;
PORTB=0Xf0;
}

void delay(uint z)
{
uint i,j;
for(i=0;i<z;i++);
for(j=0;j<2770;j++);
}

uchar SCI_R(void)
{
  while(SCI0SR1_RDRF)
{
  SCI0SR1_RDRF=1;
  return SCI0DRL;
}
}

void SCI_T(uchar T_date)
{
  SCI0SR1_TC=1;
  SCI0DRL=T_date;
  delay(10);
}
void main(void)
{
  PLL();
  NORMAL_IO_INIT();
  SCI_INIT();

  EnableInterrupts;
  asm_main(); /* call the assembly function */
  delay(20);
for(;;)
{
  if(SCI0SR1_RDRF==1)
  {
SCI0SR1_RDRF=0;
numeric=SCI0DRL;
PORTB=numeric;
SCI0DRL=numeric;
  }
}
}