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ATmega32A串口通信奇怪问题

cloudou 2015-09-05 浏览量：1492

测试ATmega32A串口通信，使用内部1M振荡，
熔丝设置

通信发送ASCII码0～2，返回十六进制均为两个字节，3e 00， 4c 00， 66 00，如此简单的东西都无**常工作，令人费解。请大家帮帮忙，谢谢啦！
//ICC-AVR application builder : 2015-09-05 10:23:35
// Target : M32
// Crystal: 1.0000Mhz

#include
#include

void USART_Transmit( unsigned char data );

void port_init(void)
{
PORTA = 0x00;
DDRA  = 0x00;
PORTB = 0x00;
DDRB  = 0x00;
PORTC = 0x00;
DDRC  = 0x00;
PORTD = 0x00;
DDRD  = 0x00;
}

//UART0 initialize
// desired baud rate: 9600
// actual: baud rate:9615 (0.2%)
void uart0_init(void)
{
UCSRB = 0x00; //disable while setting baud rate
UCSRA = 0x02;
UCSRC = BIT(URSEL) | 0x06;
UBRRL = 0x0C; //set baud rate lo
UBRRH = 0x00; //set baud rate hi
UCSRB = 0x98;
}

#pragma interrupt_handler uart0_rx_isr:iv_USART0_RXC
void uart0_rx_isr(void)
{
//uart has received a character in UDR
unsigned char i=0;
i=UDR;
USART_Transmit(i);
}

//call this routine to initialize all peripherals
void init_devices(void)
{
//stop errant interrupts until set up
CLI(); //disable all interrupts
port_init();
uart0_init();

MCUCR = 0x00;
GICR  = 0x00;
TIMSK = 0x00; //timer interrupt sources
SEI(); //re-enable interrupts
//all peripherals are now initialized
}

void USART_Transmit( unsigned char data )
{
/* 等待发送缓冲器为空 */
while ( !( UCSRA & (1<
;
/* 将数据放入缓冲器，发送数据 */
UDR = data;
}

void main(void)
{
init_devices();
while(1)
{
}
}

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