uart_fifo.zip_51 uart fifo_51 串口fifo_fifo_uart fifo_uart_fifo

/* */ #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()); } } }