串口中断fifo.c

使用华邦单片机的串口程序

#include <reg52.h>

/* UART Buffer Defines */
#define UART_RX_BUFFER_SIZE 16 /* 1,2,4,8,16,32,64,128 or 256 bytes */
#define UART_RX_BUFFER_MASK ( UART_RX_BUFFER_SIZE - 1 )
#define UART_TX_BUFFER_SIZE 16 /* 1,2,4,8,16,32,64,128 or 256 bytes */
#define UART_TX_BUFFER_MASK ( UART_TX_BUFFER_SIZE - 1 )



/* Static Variables */
static  data unsigned char UART_RxBuf[UART_RX_BUFFER_SIZE];
static data volatile unsigned char UART_RxHead;
static data volatile unsigned char UART_RxTail;
static  data unsigned char UART_TxBuf[UART_TX_BUFFER_SIZE];
static data volatile unsigned char UART_TxHead;
static data volatile unsigned char UART_TxTail;
bit fSeri0_Send_Ok;
/* initialize UART */

//t2 做波特率发生器 9600bps at 11.0592 MHz
void InitUART(  ) 
{
unsigned char x;

T2CON = 0x30;    //t2 做波特率发生器            

TH2 = 0xFF;
    TL2 = 0xdc;         
    RCAP2H = 0xFF;       
    RCAP2L = 0xdc;

    SCON = 0x50;        /* SM0 SM1 SM2 REN TB8 RB8 TI RI:9 bit */ 
    PCON = 0x00;        /* baut rate, 80h:double; 00h: normal  */ 
    ES = 1;             /* 串口中断允许   1-enable             */
    PS = 0;             /* 串口中断优先级 1-高，0-低           */
    TR2 = 1;            /* Start T2 as baut rate generator     */     

x = 0; /* flush receive buffer */
UART_RxTail = x;
UART_RxHead = x;
UART_TxTail = x;
UART_TxHead = x;
}

/* interrupt handlers */
void UART_interrupt( void ) interrupt 4
{
if (TI) 
{ // 是否是发送中断
unsigned char tmptail;
TI=0;
if (UART_TxTail==UART_TxHead)
{
fSeri0_Send_Ok=0;        /*已发送完毕*/

}
else
{
tmptail = ( UART_TxTail + 1 ) & 
UART_TX_BUFFER_MASK;
UART_TxTail = tmptail; /* store new index */
SBUF = UART_TxBuf[tmptail]; /* start 
transmition */ 
}


}
if (RI)
{
unsigned char revdata;
unsigned char tmphead;
RI=0;
revdata = SBUF; 

tmphead = ( UART_RxHead + 1 ) & UART_RX_BUFFER_MASK;
UART_RxHead = tmphead; /* store new index */
UART_RxBuf[tmphead] = revdata; /* store received data in 
buffer */ 
}
}


unsigned char ReceiveByte( void )
{
unsigned char tmptail;

while ( UART_RxHead == UART_RxTail ) /* wait for incomming data */
;
tmptail = ( UART_RxTail + 1 ) & UART_RX_BUFFER_MASK;/* calculate 
buffer index */
UART_RxTail = tmptail; /* store new index */
return UART_RxBuf[tmptail]; /* return data */
}

void TransmitByte( unsigned char senddata )
{
unsigned char tmphead;
tmphead = ( UART_TxHead + 1 ) & UART_TX_BUFFER_MASK; 

UART_TxBuf[tmphead] = senddata; /* store data in buffer */
UART_TxHead = tmphead; /* store new index */
if(fSeri0_Send_Ok==0)

{
fSeri0_Send_Ok=1;
TI=1;
}
}

unsigned char DataInReceiveBuffer( void )
{
return ( UART_RxHead != UART_RxTail ); 

}
void main(void)
{
InitUART() ;
EA=1;

while(1)
{

if (DataInReceiveBuffer())
{
TransmitByte(ReceiveByte());
}
}

}