飞思卡尔mc9s12的串口通信
我的程序可以发送数据，但是不能接收数据。请问是为什么，我把代码贴出来吧。我发现里边rdrf一旦进入中断后就自动变为0，而且不管我怎么赋值，也不能改变sci0sr1_rdrf的值，请问谁知道是为什么呢？
#include <hidef.h> /* common defines and macros */
#include "headers/uart.h"
void main(void) {
UART_s8Init(Duart0, 9600);
EnableInterrupts;
UART_s8SendByte( Duart0, 2 );
for(;;) {
_FEED_COP(); /* feeds the dog */
} /* loop forever */
/* please make sure that you never leave main */
}
#include "headers\uart.h"
#include <mc9s12dg128.h>
#pragma LINK_INFO DERIVATIVE "mc9s12dg128"
#if (Duart_UART0_used)
volatile static U8 u8Uart0_RxBuffer[Duart_BUFFER_SIZE_RX];
volatile static U8 u8Uart0_RxB_indexin=0;
volatile static U8 u8Uart0_RxB_indexout=0;
volatile static U8 u8Rx_0_Error=0;
#endif
S8 UART_s8Init( U8 UART_Id, U32 baudrate)
{
U16 ubrr_value=0;
#if F_UART==8000000
switch( baudrate )
{ case 2400 : ubrr_value = 207; break;
case 4800 : ubrr_value = 103; break;
case 9600 : ubrr_value = 52; break;
case 14400 : ubrr_value = 34; break;
case 19200 : ubrr_value = 25; break;
case 28800 : ubrr_value = 16; break;
case 38400 : ubrr_value = 12; break;
case 57600 : ubrr_value = 8; break;
case 76800 : ubrr_value = 6; break;
case 115200 : ubrr_value = 3; break;
case 230400 : ubrr_value = 1; break;
case 250000 : ubrr_value = 1; break;
case 500000 : ubrr_value = 0; break;
default : return( -1 );
}
#else
#error "F_UART non reconnu ou non defini !"
#endif
#if (Duart_UART0_used)
if(UART_Id==Duart0)
{
SCI0BDH=(ubrr_value>>8) & 0xFF;
SCI0BDL=ubrr_value& 0xFF;
SCI0CR1=0x00; // SCICR1: LOOPS=0,SCISWAI=0,RSRC=0,M=0,WAKE=0,ILT=0,PE=0,PT=0
SCI0CR2=0x2C; // enable tx et rx interrupts
}
#endif
return(0);
}
S8 UART_s8GetByte( U8 UART_Id )
{
#if (Duart_UART0_used)
if(UART_Id==Duart0)
{
if(u8Rx_0_Error==1)
{
u8Rx_0_Error=0;
return(-1); // Err Rx
}else
{
while(SCI1SR1_RDRF==0) ; //=while(!SCI1SR1_RDRF); waite until le data arrive , rdrf!=1
SCI1SR1_RDRF=1;
return SCI1DRL;
}
}
#endif
}
