AVR serial port transmission and reception using circular linked list program source code

http://www.rayfile.com/files/062cd042-d7a5-11df-8a51-0015c55db73d/

 

Key code:

UART.h:

/********** Serial port transmit and receive circular linked list implementation********
* Version..........: 1.0
* Author..........: Chen Lidong
* Target.......: ATmega128
* File name..........: UART.h
* Compiler.....: IAR for AVR V5.5
* Creation time.....: 2010.10.14
* Last modified.....: 2010.10.14
******************************************/
#ifndef __UART_H__
#define __UART_H__

#include 
#include "../main.h"    /* F_CPU */

#define UART_BAUD                9600         //波特率


#define UART_TXBUF_LENGTH        500
#define UART_RXBUF_LENGTH        500

struct UART_BUF
{
    volatile unsigned char data;
    volatile struct UART_BUF *next;
};

extern void UART_Init(void);
extern void UART_TxByte(unsigned char _data);
extern void _enable_uart_interrupt(void);
extern void _disable_uart_interrupt(void);

extern volatile struct UART_BUF UART_TxBuf[UART_TXBUF_LENGTH], UART_RxBuf[UART_RXBUF_LENGTH];
extern volatile struct UART_BUF *p_TxBuf_Head, *p_TxBuf_Tail, *p_RxBuf_Head, *p_RxBuf_Tail;


#endif /* __UART_H__ */

 

UART.c:

/********** Serial port transmit and receive circular linked list implementation********
* Version..........: 1.0
* Author..........: Chen Lidong
* Target.......: ATmega128
* File name..........: UART.c
* Compiler.....: IAR for AVR V5.5
* Creation time.....: 2010.10.14
* Last modified.....: 2010.10.14
******************************************/
#include "UART.h"

volatile struct UART_BUF UART_TxBuf[UART_TXBUF_LENGTH], UART_RxBuf[UART_RXBUF_LENGTH];
volatile struct UART_BUF *p_TxBuf_Head, *p_TxBuf_Tail, *p_RxBuf_Head, *p_RxBuf_Tail;

void UART_Init(void)
{
    UBRR0L = (F_CPU / 16L / UART_BAUD - 1);
    UCSR0B_RXEN0 = 1;
    UCSR0B_TXEN0 = 1;
    UCSR0B_RXCIE0 = 1;
    UCSR0B_TXCIE0 = 1;

    unsigned int i = 0;
    // 
    for (i = 0; i < UART_TXBUF_LENGTH - 1; i++)
    {
        UART_T xBuf[i].next = &UART_TxBuf[i + 1];
    }
    UART_TxBuf[UART_TXBUF_LENGTH - 1].next = &UART_TxBuf[0];
    p_TxBuf_Head = &UART_TxBuf[0];
    p_TxBuf_Tail = &UART_TxBuf[0];
    //
    for (i = 0; i < UART_RXBUF_LENGTH - 1; i++)
    {
        UART_RxBuf[i].next = &UART_RxBuf[i + 1];
    }
    UART_RxBuf[UART_RXBUF_LENGTH - 1].next = &UART_RxBuf[0];
    p_RxBuf_Head = &UART_RxBuf[0];
    p_RxBuf_Tail = &UART_ RxBuf[0];

    __enable_interrupt();
}

void UART_TxByte(unsigned char _data)
{
    if (UCSR0A_UDRE0 == 1 && p_TxBuf_Head == p_TxBuf_Tail)
    {
        UDR0 = _data;
    }
    else
    {
        if (p_TxBuf_Tail->next != p_TxBuf_Head)
        {
            p_TxBuf _Tail->data = _data;
            p_TxBuf_Tail = p_TxBuf_Tail->next;
        }
    }
}

void _enable_uart_interrupt(void)
{
    UCSR0B_RXCIE0 = 1;
    UCSR0B_TXCIE0 = 1;
}

void _disable_uart_interrupt(void)
{
    UCSR0B_RXCIE0 = 0;
    UCSR0B_TXCIE0 = 0;
}

#pragma vector = USART0_TXC_vect
__interrupt void USART0_TXC(void)
{
    if (UCSR0A_UDRE0 == 1 && p_TxBuf_Head != p_TxBuf_Tail)
    {
        UDR0 = p_TxBuf_Head->data;
        p_TxBuf_Head = p_TxBuf_Head->next;
    }
}

#pragma vector = USART0_RXC_vect
__interrupt void USART0_RXC(void)
{
    if (p_RxBuf_Tail->next != p_RxBuf_Head)
    {
        p_RxBuf_Tail->data = UDR0;
        p_RxBuf_Tail = p_RxBuf_Tail->next;
    }
}

 

 

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