demo_16_4.i

AVR单片机嵌入式系统原理与应用实践例码

/*****************************************************
File name           : demo_16_4.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) 1998-2006 Pavel Haiduc, HP InfoTech S.R.L.

// Prototypes for standard I/O functions


// CodeVisionAVR C Compiler
// (C) 1998-2002 Pavel Haiduc, HP InfoTech S.R.L.

// Variable length argument list macros



typedef char *va_list;





#pragma used+

char getchar(void);
void putchar(char c);
void puts(char *str);
void putsf(char flash *str);

char *gets(char *str,unsigned int len);

void printf(char flash *fmtstr,...);
void sprintf(char *str, char flash *fmtstr,...);
void snprintf(char *str, unsigned int size, char flash *fmtstr,...);
void vprintf (char flash * fmtstr, va_list argptr);
void vsprintf (char *str, char flash * fmtstr, va_list argptr);
void vsnprintf (char *str, unsigned int size, char flash * fmtstr, va_list argptr);
signed char scanf(char flash *fmtstr,...);
signed char sscanf(char *str, char flash *fmtstr,...);




                                   

            


#pragma used-

#pragma library stdio.lib


// 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-



// TWSR values (not bits) 



void I2C_init(void)
{
    TWSR=0x00;    // 2 Wire Bus initialization
    TWBR=0x00;    // Generate Acknowledge Pulse:On
    TWAR=0x00;    // 2 Wire Bus Slave Address:0h
    TWCR=0x44;    // General Call Recognition:Off,Bit Rate: 250.000 kHz
}

unsigned char I2C_start(void)               //产生启动信号
{
  TWCR = (1<<7 )|(1<<5 )|(1<<2 );
  while (!(TWCR & (1<<7 ))){};
  return 1;
}

void I2C_stop(void)                         //产生停止信号
{
  TWCR = (1<<7 )|(1<<2 )|(1<<4 );
}

unsigned char I2C_write(unsigned char c)    //向总线写一字节,并返回有无应答
{
    unsigned char ack=1;
    TWDR = c;
    TWCR = (1<<7 )|(1<<2 );
    while (!(TWCR & (1<<7 ))){};
    if((TWSR & 0xF8) != 0x18        )
        ack = 0;
    return ack;  
}

unsigned char I2C_read(unsigned char ack)   //读一字节 ack: 1时应答，0时不应答
{
    if (ack)
        TWCR = (1<<7 )|(1<<2 )|(1<<6 );    
    else
        TWCR = (1<<7 )|(1<<2 );
    while (!(TWCR & (1<<7 ))){};    
    return(TWDR);  
}

void EEprom_Page_write(unsigned int Addr,unsigned char n, unsigned char* arr)
{
    unsigned char i;
    I2C_start();					// 发起始信号
    I2C_write(0xa0);	// 发写从机写寻址字节
    I2C_write(Addr>>8);				// 发存储单元地址高字节
    I2C_write(Addr);				// 发存储单元地址低字节
    for (i=1;i<=n;i++)
    {
        I2C_write(*arr);			// 写一个字节数据到24C256
        arr++;
    }    
    I2C_stop();				// 发停止信号
    delay_ms(10);			// 等待10ms，保证24C256内部写操作完成再进行新操作
}

void EEprom_Write(unsigned int Addr,unsigned char n, unsigned char* arr)
{
    unsigned char n_tmp;
    n_tmp=64          -(unsigned char)(Addr&64          -1 );
    if ((n>n_tmp)&&(n_tmp!=0))
    {
        EEprom_Page_write(Addr,n_tmp,arr);
        Addr += n_tmp;
        n -= n_tmp;
        arr += n_tmp;
    }
    while (n >= 64          )
    {
        EEprom_Page_write(Addr,64          , arr);
        Addr += 64          ;
        n -= 64          ;
        arr += 64          ;
    }
    if (n!=0)
        EEprom_Page_write(Addr,n,arr);
}

void EEprom_read(unsigned int Addr,unsigned char n, unsigned char* arr)
{
    unsigned char i;
    I2C_start();						// 发起始信号
    I2C_write(0xa0);		// 发写从机写寻址字节
    I2C_write(Addr>>8); 				// 发存储单元地址高字节
    I2C_write(Addr);					// 发存储单元地址低字节
    I2C_start();   						// 发起始信号
    I2C_write(0xa0 | 1);	// 发从机读寻址字节    
    for (i=1;i<=n-1;i++)
    {
        *arr = I2C_read(1);			// 读一个字节数据，返回ACK   
        arr++;
    }
    *arr=I2C_read(0);				// 读最后一个字节数据，返回NO ACK
    I2C_stop();						// 发停止信号
}

void main(void)
{
    unsigned char i,data[200];
    
    UCSRA=0x00;		// USART initialization
    UCSRB=0x18;		// Communication Parameters: 8 Data, 1 Stop, No Parity
    UCSRC=0x86;		// USART Receiver: On，USART Transmitter: On
    UBRRH=0x00;		// USART Mode: Asynchronous	，USART Baud Rate: 9600
    UBRRL=0x19; 
    // ================================================
    I2C_init();		                    // initialize the I2C bus
    for (i=0;i<200;i++) {data[i]=i;}    // 数组赋值
    EEprom_Write(0x0aa,200,data);       // 从0x00aa起写200个字节
    for (i=0;i<200;i++) {data[i]=0;}    // 数组清零
    EEprom_read(0x0aa,200,data);        // 从0x00aa起读200个字节
    for (i=0;i<200;i++) {putchar(data[i]);} // 送PC检验
    while (1){};
}