mcp2510.c

用iccavr工具编写的mcp2510与can连接的通讯程序。

//ICC-AVR application builder : 2007-10-17 16:47:59
// Target : M16
// Crystal: 16.000Mhz

#include <iom16v.h>
#include <macros.h>
#define READ 0x03 // 读MCP2510指令代码 
#define WRITE 0x02 // 写MCP2510指令代码 
#define RESET 0xC0 // 复位MCP2510指令代码 
#define RTS 0x80 // MCP2510请求发送指令代码 
#define STA2510 0xA0 // 读MCP2510状态指令代码 
#define BITMOD 0x05 // MCP2510位修改指令代码 
int timecount;
int a[]; // SPI发送或接收数据寄存器
int b[]; // 发送或接收的数据
int c[]; // 发送或接收的数据
int i; // 临时变量
int count; // 发送接收计数器
int count1=0; // for test
int RecID_H=0;
int RecID_L=0;
int DLC;

void port_init(void)
{
 PORTA = 0xFF;
 DDRA  = 0x00;
 PORTB = 0xFF;
 DDRB  = 0x00;
 PORTC = 0xFF; //m103 output only
 DDRC  = 0x00;
 PORTD = 0xFF;
 DDRD  = 0x00;
}

//TIMER0 initialize - prescale:1
// WGM: Normal
// desired value: 100KHz
// actual value: 100.000KHz (0.0%)
void timer0_init(void)
{
 TCCR0 = 0x00; //stop
 TCNT0 = 0x60; //set count
 OCR0  = 0xA0;  //set compare
 TCCR0 = 0x01; //start timer
}

#pragma interrupt_handler timer0_comp_isr:20
void timer0_comp_isr(void)
{/*int i=0;
 timecount=0;
 timecount++;
if (timecount>=1000) timecount=0;
SPDR=READ;
SPDR=0x66;
b[i]=SPDR;
b[i++]=SPDR;
 while(!(SPSR & (1<<SPIF)))*/
  ;
 //compare occured TCNT0=OCR0
}

//TIMER1 initialize - prescale:1
// WGM: 0) Normal, TOP=0xFFFF
// desired value: 100KHz
// actual value: 100.000KHz (0.0%)
void timer1_init(void)
{
 TCCR1B = 0x00; //stop
 TCNT1H = 0xFF; //setup
 TCNT1L = 0x60;
 OCR1AH = 0x00;
 OCR1AL = 0xA0;
 OCR1BH = 0x00;
 OCR1BL = 0xA0;
 //OCR1CH = $OCR1CH$;
 //OCR1CL = $OCR1CL$;
 ICR1H  = 0x00;
 ICR1L  = 0xA0;
 TCCR1A = 0x50;
 TCCR1B = 0x01; //start Timer
}

//TIMER2 initialize - prescale:1
// WGM: Normal
// desired value: 100KHz
// actual value: 100.000KHz (0.0%)
void timer2_init(void)
{
 TCCR2 = 0x00; //stop
 ASSR  = 0x00; //set async mode
 TCNT2 = 0x60; //setup
 OCR2  = 0xA0;
 TCCR2 = 0x11; //start
}

//SPI initialize
// clock rate: 4000000hz
void spi_init(void)
{
 SPCR = 0x50; //setup SPI
 SPSR = 0x00; //setup SPI
}

//ADC initialize
// Conversion time: 3uS
void adc_init(void)
{
 ADCSR = 0x00; //disable adc
 ADMUX = 0x00; //select adc input 0
 ACSR  = 0x80;
 ADCSR = 0xE2;
}

//call this routine to initialize all peripherals
void init_devices(void)
{
 //stop errant interrupts until set up
 CLI(); //disable all interrupts
 port_init();
 timer0_init();
 timer1_init();
 timer2_init();
 spi_init();
 adc_init();

 MCUCR = 0x00;
 GICR  = 0x00;
 TIMSK = 0x02; //timer interrupt sources
 SEI(); //re-enable interrupts
 //all peripherals are now initialized
}


void SPIINT()// SPI中断服务子程序 
{
SPSR=0x00;
a[i++]=SPDR; // 数据暂存a[]中 
count-=1;
if(count>0) SPDR=a[i];// 未发送完，继续 
else PORTB|=BIT(PB4);//否则，片选信号置高电平 
return;
}


void SPIEXCHANGE(count)// 启动SPI传送 
int count;
{
if(count>0) { // 有数据可送？ 
i=0,i=i++;
PORTB&=~BIT(PB4); // 片选位置低电平 
SPDR=a[i];       // 送数 
}
else
;                   // 否则，空操作，并返回 
return;
}

void WAIT_SPI()// 等待SPI传送完成 
{
do{
;
}while(count>0); // 当count!=0时，等待 to add "CLRWDT" 
return;
}
 
void RESET2510()//对MCP2510芯片进行复位 
{
a[0]=RESET;
count=1;
SPIEXCHANGE(count); // 送复位指令 
WAIT_SPI();
return;
}

void RD2510(adress,n)//从地址