getcharserial.c

altera串口源代码程序

/**************************************************/
//
//  getcharSerial() - Read char from RxBuf
//
//       If no char  to be read then returns a -1
//
/**************************************************/
#include "buffer.h"

//Globals variables
extern unsigned char RxBuf[RXBUFSIZE];	// the receiver buffer.
extern int RxHead;			// the circular buffer index
extern int RxTail;

int getcharSerial() 
{
   int temp = -1;
   if (RxTail != RxHead)    
   {
      temp = RxBuf[RxTail];
      if (++RxTail > (RXBUFSIZE -1))
      {
         RxTail = 0;
      }
   }

   return(temp);
}