我想问问大家达人关于uart（RS232）通信协议编程中要注意的地方。
最近在用mega64的uart0端口于sim100模块的通信中发生了些问题。我用iccavr自动生成程序，然后自己按照mega64的说明书上加了1段发送和1段接受程序，但是在单步调试的过程中发现总是不能正常的进入发送程序。如果能有程序示例给我看下最好，谢谢。 //ICC-AVR application builder : 2005-6-21 9:31:40
// Target : M64
// Crystal: 8.0000Mhz
#include <iom64v.h>
#include <macros.h>
#define FRAMING_ERROR (1<<FE1)
#define PARITY_ERROR (1<<UPE1)
#define DATA_OVERRUN (1<<DOR1)
#define DATA_REGISTER_EMPTY (1<<UDRE1)
#define RX_COMPLETE (1<<RXC1)
#define UART_BEGIN_STX 0xBB
#define UART_END_STX 0xEE
#define RX_BUFFER_SIZE1 8
#pragma interrupt_handler uart1_rx_isr:iv_USART1_RXC
void delay_nus(unsigned int n);
void delay_nms(unsigned int n);
void port_init(void);
void uart1_init(void);
void uart1_rx_isr(void);
void init_devices(void);
// USART1 Receiver buffer
char rx_buffer1;
unsigned char rx_counter;
// This flag is set on USART0 Receiver buffer overflow
int Uart_RecvFlag;
void port_init(void)
{
PORTA = 0xFF;
DDRA= 0x00;
PORTB = 0xFF;
DDRB= 0x00;
PORTC = 0xFF; //m103 output only
DDRC= 0x00;
PORTD = 0xFF;
DDRD= 0x00;
PORTE = 0xFF;
DDRE= 0x00;
PORTF = 0xFF;
DDRF= 0x00;
PORTG = 0x1F;
DDRG= 0x00;
}
//UART0 initialisation
// desired baud rate: 9600
// actual: baud rate:9615 (0.2%)
// char size: 8 bit
// parity: Disabled
void uart1_init(void)
{
UCSR1B = 0x00; //disable while setting baud rate
UCSR1A = 0x00;
UCSR1C = 0x06;
UBRR1L = 0x33; //set baud rate lo
UBRR1H = 0x00; //set baud rate hi
UCSR1B = 0x90;
}
void uart1_rx_isr(void)
{
char status,data;
//uart has received a character in UDR
status=UCSR1A;
data=UDR1;
if ((status & (FRAMING_ERROR | PARITY_ERROR | DATA_OVERRUN))==0)
{
if (!Uart_RecvFlag)
{
rx_buffer1 = data;
switch (rx_counter)
{
case 0:
if (data == UART_BEGIN_STX) rx_counter = 1;
break;
case 1:
case 2:
case 3:
case 4:
rx_counter++;
break;
case 5:
rx_counter = 0;
if (data == UART_END_STX)Uart_RecvFlag = 1;
break;
}
}
}
else
rx_counter = 0;
}
//call this routine to initialise all peripherals
void init_devices(void)
{
//stop errant interrupts until set up
CLI(); //disable all interrupts
XDIV= 0x00; //xtal divider
XMCRA = 0x00; //external memory
port_init();
uart1_init();
MCUCR = 0x00;
EICRA = 0x00; //extended ext ints
EICRB = 0x00; //extended ext ints
EIMSK = 0x00;
TIMSK = 0x00; //timer interrupt sources
ETIMSK = 0x00; //extended timer interrupt sources
SEI(); //re-enable interrupts
}
void main(void)
{
init_devices();
DDRF=0x07;
PORTF=0x00;
while(1)
{
if (Uart_RecvFlag)
{
PORTF |= BIT(PF0);
delay_nms(1000);
PORTF &= ~BIT(PF0);
delay_nms(1000);//处理收到的数据包
Uart_RecvFlag = 0; //允许USART接受新的数据包
}
//处理其它任务
}
SEI();
}
void delay_nus(unsigned int n)//n微秒延时函数
{
unsigned int i;
for (i=0;i<n;i++)
{
asm("nop");
}
}
void delay_nms(unsigned int n)
{
unsigned int i;
for(i=0;i<n;i++)
{
delay_nus(1000);
}
}
上面这段是我自己编的一段程序，但是似乎就是进不了uart1的中断程序，想问问大家大概是哪里有问题？
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