標題:
AVR單片機的TWI中斷模式
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作者:
找你玩
時間:
2018-2-8 09:43
標題:
AVR單片機的TWI中斷模式
使用AVR單片機內部的TWI功能,并采用中斷工作模式,可以很好的使用Atmega系列的內部資源,并提高程序的穩(wěn)定性;
#include <BCD.h>
unsigned char i2c_sla;
unsigned char i2c_addrh,i2c_addrl;
unsigned char i2c_wr;
unsigned char i2c_sub_flag;
unsigned char i2c_num;
unsigned char *i2c_buf;
unsigned char i2c_end;
/***********************************************************************************************************************************************************************
函數(shù)名稱:interrupt [TWI] void twi_isr(void)
函數(shù)功能:i2c底層中斷處理函數(shù)(時鐘SD2201和AT24C256共同的)
***********************************************************************************************************************************************************************/
interrupt [TWI] void twi_isr(void)
{
unsigned char i2c_sta,tmp = 0;
i2c_sta = TWSR;
switch(i2c_sta)
{
case 0x08:
if(i2c_sub_flag == 1)
{
TWDR = i2c_sla&0xfe;
}
else
{
TWDR = i2c_sla;
}
//TWCR &= 0xcf;
//TWCR |= 0x80;
TWCR = 0x85;
break;
case 0x10:
TWDR = i2c_sla;
//TWCR &= 0xcf;
//TWCR |= 0x80;
TWCR = 0x85;
//i2c_sub_flag = 1;
break;
case 0x18:
if(i2c_sub_flag == 0)
{
if(i2c_num > 0)
{
TWDR = *i2c_buf;
//TWCR &= 0xcf;
//TWCR |= 0x80;
TWCR = 0x85;
i2c_buf++;
i2c_num--;
}
else
{
//TWCR &= 0xdf;
//TWCR |= 0x90;
TWCR = 0x95;
i2c_end = 1;
}
}
if(i2c_sub_flag == 1)
{
TWDR = i2c_addrh;
//TWCR &= 0xcf;
//TWCR |= 0x80;
TWCR = 0x85;
i2c_sub_flag = 2;
}
break;
case 0x28:
if(i2c_sub_flag == 3)
{
if(i2c_wr == 0)
{
if(i2c_num > 0)
{
TWDR = *i2c_buf;
i2c_buf++;
//TWCR &= 0xcf;
//TWCR |= 0x80;
TWCR = 0x85;
i2c_num--;
}
else
{
//TWCR &= 0xdf;
//TWCR |= 0x90;
TWCR = 0x95;
i2c_end = 1;
}
}
}
if(i2c_sub_flag == 2)
{
TWDR = i2c_addrl;
//TWCR &= 0xcf;
//TWCR |= 0x80;
TWCR = 0x85;
i2c_sub_flag = 3;
}
if(i2c_sub_flag == 3)
{
if(i2c_wr == 1)
{
//TWCR &= 0xef;
//TWCR |= 0xa0;
TWCR = 0xa5;
}
}
if(i2c_sub_flag == 0)
{
if(i2c_num > 0)
{
TWDR = *i2c_buf;
//TWCR &= 0xcf;
//TWCR |= 0x80;
TWCR = 0x85;
i2c_buf++;
i2c_num--;
}
else
{
//TWCR &= 0xdf;
//TWCR |= 0x90;
TWCR = 0x95;
i2c_end = 1;
}
}
break;
case 0x20:
case 0x30:
case 0x48:
i2c_end = 0xff;
//TWCR &= 0xfe;
break;
case 0x38:
TWCR &= 0xed;
TWCR |= 0xa4;
i2c_end = 0xfe;
//TWCR &= 0xfe;
break;
case 0x40:
//TWCR &= 0xcf;
//TWCR |= 0xc0;
TWCR = 0xc5;
break;
case 0x50:
*i2c_buf = TWDR;
i2c_buf++;
i2c_num--;
if(i2c_num == 0)
{
//TWCR &= 0x8f;
//TWCR |= 0x80;
TWCR = 0x85;
}
else
{
//TWCR &= 0xcf;
//TWCR |= 0xc0;
TWCR = 0xc5;
}
break;
case 0x58:
tmp = TWDR;
//TWCR &= 0xdf;
//TWCR |= 0x90;
TWCR = 0x95;
i2c_end = 1;
break;
default:
TWCR &= 0xfe;
break;
}
}
/***********************************************************************************************************************************************************************
函數(shù)名稱:void tran_dat(unsigned char *a,unsigned char num,unsigned char fx)
函數(shù)功能:i2c傳輸數(shù)據(jù)是由MSB開始LSB結束,而SD2201的數(shù)據(jù)傳輸是由LSB開始MSB結束,此函數(shù)負責數(shù)據(jù)做此轉換的
函數(shù)參數(shù):unsigned char *a 數(shù)據(jù)的啟始指針,
unsigned char num 數(shù)據(jù)的字節(jié)個數(shù)
unsigned char fx 時鐘寫和讀的標志位, 1-寫,0-讀
***********************************************************************************************************************************************************************/
void tran_dat(unsigned char *a,unsigned char num,unsigned char fx)
{
unsigned char j,k,dat;
for(j = 0;j < num;j++)
{
dat = *a;
if(fx == 1)
{
*a = bin2bcd(dat);
}
dat = *a;
*a = 0;
*a |= dat & 0x01;
for(k = 1;k < 8;k++)
{
*a <<= 1;
dat >>= 1;
*a |= dat & 0x01;
}
dat = *a;
if(fx == 0)
{
if((j == 4)&&(num == 7))
{
dat &= 0x3f;
}
if((j == 0)&&(num == 3))
{
dat &= 0x3f;
}
*a = bcd2bin(dat);
}
a++;
}
}
/***********************************************************************************************************************************************************************
函數(shù)名稱:unsigned char i2c_w_n(unsigned char sla,unsigned char *s,unsigned char num)
函數(shù)功能:無子地址寫入N字節(jié)數(shù)據(jù)
函數(shù)參數(shù):unsigned char sla 器件地址
unsigned char *s 寫入數(shù)據(jù)緩沖區(qū)指針
unsigned char num 寫入數(shù)據(jù)個數(shù)
***********************************************************************************************************************************************************************/
unsigned char i2c_w_n(unsigned char sla,unsigned char *s,unsigned char num)
{
i2c_sla = sla;
i2c_buf = s;
i2c_num = num;
i2c_sub_flag = 0;
i2c_end = 0;
TWCR=0xa5;
while(i2c_end == 0);
if(i2c_end == 1)
{
delay_ms(10);
return(1);
}
else
{
return(0);
}
}
/***********************************************************************************************************************************************************************
函數(shù)名稱:unsigned char i2c_rec_n(unsigned char sla,unsigned char *s,unsigned char num)
函數(shù)功能:無子地址讀出N字節(jié)數(shù)據(jù)
函數(shù)參數(shù):unsigned char sla 器件地址
unsigned char *s 讀出數(shù)據(jù)緩沖區(qū)指針
unsigned char num 讀出數(shù)據(jù)個數(shù)
***********************************************************************************************************************************************************************/
unsigned char i2c_rec_n(unsigned char sla,unsigned char *s,unsigned char num)
{
i2c_sla = sla + 1;
i2c_buf = s;
i2c_num = num;
i2c_sub_flag = 0;
i2c_end = 0;
TWCR=0xa5;
while(i2c_end == 0);
if(i2c_end == 1)
{
return(1);
}
else
{
return(0);
}
}
/***********************************************************************************************************************************************************************
函數(shù)名稱:unsigned char i2c_w_subn(unsigned char sla,unsigned char ah,unsigned char al,unsigned char *s,unsigned char num)
函數(shù)功能:有子地址寫入N字節(jié)數(shù)據(jù)
函數(shù)參數(shù):unsigned char sla 器件地址
unsigned char ah 器件子地址高字節(jié)
unsigned char al 器件子地址低字節(jié)
unsigned char *s 寫入數(shù)據(jù)緩沖區(qū)指針
unsigned char num 寫入數(shù)據(jù)個數(shù)
***********************************************************************************************************************************************************************/
unsigned char i2c_w_subn(unsigned char sla,unsigned char ah,unsigned char al,unsigned char *s,unsigned char num)
{
i2c_sla = sla;
i2c_buf = s;
i2c_num = num;
i2c_addrh = ah;
i2c_addrl = al;
i2c_wr = 0;
i2c_sub_flag = 1;
i2c_end = 0;
TWCR=0xa5;
while(i2c_end == 0);
if(i2c_end == 1)
{
delay_ms(10);
return(1);
}
else
{
return(0);
}
}
/***********************************************************************************************************************************************************************
函數(shù)名稱:unsigned char i2c_rec_subn(unsigned char sla,unsigned char ah,unsigned char al,unsigned char *s,unsigned char num)
函數(shù)功能:無子地址讀出N字節(jié)數(shù)據(jù)
函數(shù)參數(shù):unsigned char sla 器件地址
unsigned char ah 器件子地址高字節(jié)
unsigned char al 器件子地址低字節(jié)
unsigned char *s 讀出數(shù)據(jù)緩沖區(qū)指針
unsigned char num 讀出數(shù)據(jù)個數(shù)
***********************************************************************************************************************************************************************/
unsigned char i2c_rec_subn(unsigned char sla,unsigned char ah,unsigned char al,unsigned char *s,unsigned char num)
{
i2c_sla = sla + 1;
i2c_buf = s;
i2c_num = num;
i2c_addrh = ah;
i2c_addrl = al;
i2c_wr = 1;
i2c_sub_flag = 1;
i2c_end = 0;
TWCR=0xa5;
while(i2c_end == 0);
if(i2c_end == 1)
{
return(1);
}
else
{
return(0);
}
}
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作者:
yi1liang
時間:
2018-3-11 06:48
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