一个非常好的串口程序
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一个非常好的串口程序[转帖]
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＃i nclude "uart.h"
/* USART Buffer Defines */
#define USART_RX_BUFFER_SIZE 16 /* 1,2,4,8,16,32,64,128 or 256 bytes */ #define USART_RX_BUFFER_MASK ( USART_RX_BUFFER_SIZE - 1 )
#define USART_TX_BUFFER_SIZE 16 /* 1,2,4,8,16,32,64,128 or 256 bytes */ #define USART_TX_BUFFER_MASK ( USART_TX_BUFFER_SIZE - 1 )
#if ( USART_RX_BUFFER_SIZE & USART_RX_BUFFER_MASK )
#error RX buffer size is not a power of 2
#endif
/* Static Variables */
static unsigned char USART_RxBuf[USART_RX_BUFFER_SIZE];
static volatile unsigned char USART_RxHead;
static volatile unsigned char USART_RxTail;
static unsigned char USART_TxBuf[USART_TX_BUFFER_SIZE];
static volatile unsigned char USART_TxHead;
static volatile unsigned char USART_TxTail;
/* 串口初始化*/
void InitUSART(INT8U baudrate)
{
INT8U x;
UBRR0L = baudrate;
UCSR0B = ( (1< x = 0; /* flush receive buffer */ USART_RxTail = x; USART_RxHead = x; USART_TxTail = x; USART_TxHead = x; } /* 接收中断*/ void USART_RX_interrupt( void ) { unsigned char data; unsigned char tmphead; data = UDR0; /* read the received data */ tmphead = ( USART_RxHead + 1 ) & USART_RX_BUFFER_MASK;/* calculate buffer index */ USART_RxHead = tmphead; /* store new index */ if ( tmphead == USART_RxTail ) { return;/* ERROR! Receive buffer overflow, you can use flux cortorl */ } USART_RxBuf[tmphead] = data; /* store received data in buffer */ } /* 发送中断*/ void USART_TX_interrupt( void ) { unsigned char tmptail; if ( USART_TxHead != USART_TxTail )/* check if all data is transmitted */ { tmptail = ( USART_TxTail + 1 ) & USART_TX_BUFFER_MASK;/* calculate buffer index */ USART_TxTail = tmptail; /* store new index */ UDR0 = USART_TxBuf[tmptail]; /* start transmition */ } else { UCSR0B &= ~(1< } } /* 读取数据函数*/ unsigned char ReceiveByte( void ) { unsigned char tmptail; while ( USART_RxHead == USART_RxTail ) /* wait for incomming data */ ; tmptail = ( USART_RxTail + 1 ) & USART_RX_BUFFER_MASK;/* calculate buffer index */ USART_RxTail = tmptail; /* store new index */ return USART_RxBuf[tmptail]; /* return data */ } /* 发送数据函数*/ void TransmitByte( unsigned char data ) { unsigned char tmphead; tmphead = ( USART_TxHead + 1 ) & USART_TX_BUFFER_MASK; /* calculate buffer index */ while ( tmphead == USART_TxTail )/* wait for free space in buffer */ ; USART_TxBuf[tmphead] = data; /* store data in buffer */ USART_TxHead = tmphead; /* store new index */ UCSR0B |= (1< } /* 查询是否有数据*/ unsigned char DataInReceiveBuffer( void ) {