本帖最后由 shencai555 于 2009-12-18 14:05 编辑
file:///e:/ppp.jpg 这是我画的图，但在运行时发现有电平冲突，请指教
代码(ICCAVR7.14)
//ICC-AVR application builder : 2009-12-14 15:17:18
// Target : M8
// Crystal: 6.0000Mhz
#include <iom8v.h>
#include <macros.h>
unsigned char key;
void port_init(void)
{
PORTB = 0x00;
DDRB = 0x00;
PORTC = 0xf8; //m103 output only
DDRC = 0x07;//端口C的低三位输出0，配合74LS20产生中断
PORTD = 0xF0;
DDRD = 0xF0;//端口D的高四位输出1，配合74LS20产生中断
}
#pragma interrupt_handler int0_isr:iv_INT0
void int0_isr(void)
{
CLI();
DDRC&=0xf8;//端口C的低三位输入
if(PINC&0x01)key=0;
else if(PINC&0x02)key=4;
else if(PINC&0x04)key=8;
DDRC|=0x07;
PORTC|=0x07;
DDRD&=0x0f;
PORTD&=0x0f;
if(PIND&0x10)key+=0;
else if(PIND&0x20)key+=1;
else if(PIND&0x40)key+=2;
else if(PIND&0x80)key+=3;
DDRC=0x07;
PORTC&=0xf8;
DDRD|=0xf0;
DDRD|=0xf0;
putchar(key);
SEI();
//external interupt on INT0
}
//call this routine to initialize all peripherals
void init_devices(void)
{
//stop errant interrupts until set up
CLI(); //disable all interrupts
port_init();
MCUCR = 0x02;
GICR = 0x40;
TIMSK = 0x00; //timer interrupt sources
SEI(); //re-enable interrupts
//all peripherals are now initialized
}
//UART0 initialize
// desired baud rate: 9600
// actual: baud rate:9615 (0.2%)
void uart0_init(void)
{
UCSRB = 0x00; //disable while setting baud rate
UCSRA = 0x00;
UCSRC = BIT(URSEL) | 0x06;
UBRRL = 0x26; //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)
{
putchar(UDR);
//uart has received a character in UDR
}
void putchar(unsigned char ch)
{
while(!(UCSRA & (1<<UDRE) ) );
UDR=ch;
}
void main(void)
{
init_devices();
uart0_init();
while(1);
}
不知道是原理图有问题还是程序有问题？或者都有问题？请知道的指教一下，谢谢！ |
楼主
标题置顶
标题高亮
