demo_13_2.i

AVR单片机嵌入式系统原理与应用实践例码

/*********************************************
File name			: demo_13_2.c
Chip type           : ATmega16
Program type        : Application
Clock frequency     : 4.000000 MHz
Memory model        : Small
External SRAM size  : 0
Data Stack size     : 256
*********************************************/

// CodeVisionAVR C Compiler
// (C) 1998-2001 Pavel Haiduc, HP InfoTech S.R.L.

// I/O registers definitions for the ATmega16


#pragma used+
sfrb TWBR=0;
sfrb TWSR=1;
sfrb TWAR=2;
sfrb TWDR=3;
sfrb ADCL=4;
sfrb ADCH=5;
sfrw ADCW=4;      // 16 bit access
sfrb ADCSRA=6;
sfrb ADMUX=7;
sfrb ACSR=8;
sfrb UBRRL=9;
sfrb UCSRB=0xa;
sfrb UCSRA=0xb;
sfrb UDR=0xc;
sfrb SPCR=0xd;
sfrb SPSR=0xe;
sfrb SPDR=0xf;
sfrb PIND=0x10;
sfrb DDRD=0x11;
sfrb PORTD=0x12;
sfrb PINC=0x13;
sfrb DDRC=0x14;
sfrb PORTC=0x15;
sfrb PINB=0x16;
sfrb DDRB=0x17;
sfrb PORTB=0x18;
sfrb PINA=0x19;
sfrb DDRA=0x1a;
sfrb PORTA=0x1b;
sfrb EECR=0x1c;
sfrb EEDR=0x1d;
sfrb EEARL=0x1e;
sfrb EEARH=0x1f;
sfrw EEAR=0x1e;   // 16 bit access
sfrb UBRRH=0x20;
sfrb UCSRC=0X20;
sfrb WDTCR=0x21;
sfrb ASSR=0x22;
sfrb OCR2=0x23;
sfrb TCNT2=0x24;
sfrb TCCR2=0x25;
sfrb ICR1L=0x26;
sfrb ICR1H=0x27;
sfrb OCR1BL=0x28;
sfrb OCR1BH=0x29;
sfrw OCR1B=0x28;  // 16 bit access
sfrb OCR1AL=0x2a;
sfrb OCR1AH=0x2b;
sfrw OCR1A=0x2a;  // 16 bit access
sfrb TCNT1L=0x2c;
sfrb TCNT1H=0x2d;
sfrw TCNT1=0x2c;  // 16 bit access
sfrb TCCR1B=0x2e;
sfrb TCCR1A=0x2f;
sfrb SFIOR=0x30;
sfrb OSCCAL=0x31;
sfrb OCDR=0x31;
sfrb TCNT0=0x32;
sfrb TCCR0=0x33;
sfrb MCUCSR=0x34;
sfrb MCUCR=0x35;
sfrb TWCR=0x36;
sfrb SPMCR=0x37;
sfrb TIFR=0x38;
sfrb TIMSK=0x39;
sfrb GIFR=0x3a;
sfrb GICR=0x3b;
sfrb OCR0=0X3c;
sfrb SPL=0x3d;
sfrb SPH=0x3e;
sfrb SREG=0x3f;
#pragma used-

// Interrupt vectors definitions


// Needed by the power management functions (sleep.h)
#asm
	#ifndef __SLEEP_DEFINED__
	#define __SLEEP_DEFINED__
	.EQU __se_bit=0x40
	.EQU __sm_mask=0xB0
	.EQU __sm_powerdown=0x20
	.EQU __sm_powersave=0x30
	.EQU __sm_standby=0xA0
	.EQU __sm_ext_standby=0xB0
	.EQU __sm_adc_noise_red=0x10
	.SET power_ctrl_reg=mcucr
	#endif
#endasm


// CodeVisionAVR C Compiler
// (C) 1998-2000 Pavel Haiduc, HP InfoTech S.R.L.


#pragma used+

void delay_us(unsigned int n);
void delay_ms(unsigned int n);

#pragma used-



//计算和定义波特率设置参数

// USART控制和状态寄存器的标志位定义


flash unsigned char led_7[10]={0x3F,0x06,0x5B,0x4F,0x66,0x6D,0x7D,0x07,0x7F,0x6F};

interrupt [12] void usart_rx_isr(void)   // USART接收中断服务
{
    unsigned char status,data;
    status = UCSRA;
    data = UDR;
    if ((status & ((1<<4) | (1<<2) | (1<<3)))==0)
        PORTA = led_7[data];
}

void USART_Transmit(unsigned char data)
{
	while (!(UCSRA & (1<<5)));     // 等待发送寄存器空			                
	UDR = data;                                 // 发送数据			        
}

void main( void )
{
    unsigned char i=0;
    
    PORTA = 0x00;       // LED段码输出
    DDRA = 0xff;
    PORTD = 0x03;       // TXD(PD1)输出
    DDRD = 0x02;        // RXD(PD0)输入,上拉有效
    
    UCSRA = 0x00;       // USART初始化
    UCSRB = (1<<7         )|(1<<4)|(1<<3);     // 允许RXC中断,接收允许,发送允许
    //UCSRB = 0x98；
    UCSRC = (1<<7         )|(1<<2)|(1<<1);   // 8 Data, 1 Stop, No Parity
    //UCSRC = 0x86;
    UBRRH = (unsigned char)((unsigned int)((unsigned long)4000000			/(16*(unsigned long)9600            )-1)>>8);     // 设置波特率
    UBRRL = (unsigned char)((unsigned int)((unsigned long)4000000			/(16*(unsigned long)9600            )-1));
    #asm("sei")         // 开中断
	for(;;)
	{
		USART_Transmit( i+0x30 ); 
	    if (++i >= 10) i = 0;
		USART_Transmit(0x0d);		// 发送回车符
		USART_Transmit(0x0a);		// 发送换行符
	    delay_ms(500);
	}
}