usart接收，数据丢失问题
我用mega16发送5个字节给mega128a1时，总是接收不到最后一个字节，两者的波特率都是9600。求指导。mega16：
#ifndef F_CPU
#define F_CPU 16000000UL
#endif
#ifndef BAUD
#define BAUD 9600
#endif
#include "Anyway_uart.h"
void USART_Init(void)
{
DDRD&=0xfe;
PORTD=0xff;
/*设置波特率*/
//UBRRH = 0;
//UBRRL = 16;/*设置波特率,16M晶振,57600波特率,参考DataSheet*/
UBRRH = (((F_CPU/BAUD)/16)-1)/256;
UBRRL = (((F_CPU/BAUD)/16)-1)%256;
UCSRB |= (1<<RXEN)|(1<<TXEN)|(1<<RXCIE);
//使能发送,接收,接收中断
}
void Putc(uint8_t data)
{
/*等待发送缓冲器为空*/
while( !(UCSRA & (1<<UDRE)));
/*将数据放入缓冲区,发送数据*/
UDR = data;
while(!(UCSRA&(1<<TXC)));//等待发送完成
}
void putBuffer(uint8_t* data,uint8_t len)
{
int i;
for (i=0;i<len;i++)
{
loop_until_bit_is_set(UCSRA, UDRE);
UDR = data;
while(!(UCSRA&(1<<TXC)));//等待发送完成
}
}
void Puts(char *str)
{
while(*str!='\0')
{
Putc(*str);
str++;
}
}
int uart_putchar(char c, FILE *stream)
{
if (c == '\n')
uart_putchar('\r', stream);
loop_until_bit_is_set(UCSRA, UDRE);
UDR = c;
while(!(UCSRA&(1<<TXC)));//等待发送完成
return 0;
}
在main函数里循环发送：
while(1)
{
_delay_ms(10000);
putBuffer(request,5);
}
mega128a1：
ISR(USARTF0_RXC_vect)
{
PORTE.OUTTGL = 0x80;
//清除中断标志位
//When interrupt-driven data reception is used, the receive complete interrupt routine must read
//the received data from DATA in order to clear the RXCIF
recv = USARTF0_DATA;
printf("IRQn recv[%d]=%x\r\n",recv_count,recv);
recv_count++;
if(recv_count == 5)
{
flag = 1;
recv_count = 0;
}
}
每次都只能接收到4个数据！{:cry:}
等待发送完成后TXC写1清零试试 应该是晶振的问题！！！！！！！！
页:
[1]