使用stm32的io模拟方式操作can控制器sja1000

sja1000是一款独立的can控制器芯片，对它的操作很像操作外部存储器，8位地址数据复用线AD0~AD7，WR，RD，ALE，CS。

原本是使用stm32的fsmc来操作sja1000的，发现总有一两个寄存器数据读出来和写入的不一样，所以才改用io口模拟方式操作sja1000（别问我为什么不直接使用stm32的can控制器，因为项目需要没办法，不然stm32自带的can控制器这么好用为什么不用呢！！！）。

进入正题，贴上操作部分的源码！

void WriteSja1000(u8 addr,u8 data)

{

CLR_SJA1000_CS;

SET_DATA(addr);

SET_SJA1000_RS;

delay(10);

CLR_SJA1000_RS;

SET_DATA(data);

CLR_SJA1000_WR;

delay(10);

SET_SJA1000_WR;

SET_SJA1000_CS;

}

u8 ReadSja1000(u8 addr)

{

u8 DATA = 0;

SET_DATA(addr);

CLR_SJA1000_CS;

SET_SJA1000_RS;

delay(10);

CLR_SJA1000_RS;

CLR_SJA1000_RD;

delay(10);

DATA = GET_DATA();

SET_SJA1000_RD;

SET_SJA1000_CS;

return DATA;

}

void SET_DATA(u8 data)

{

DATALINE_OUT();//设置AD0~AD7对应的io为输出

(data & (1 << 7)) ? (GPIOE->BSRR = (1 << 10)): (GPIOE->BRR = (1 << 10));

(data & (1 << 6)) ? (GPIOE->BSRR = (1 << 9)): (GPIOE->BRR = (1 << 9));

(data & (1 << 5)) ? (GPIOE->BSRR = (1 << 8)): (GPIOE->BRR = (1 << 8));

(data & (1 << 4)) ? (GPIOE->BSRR = (1 << 7)): (GPIOE->BRR = (1 << 7));

(data & (1 << 3)) ? (GPIOD->BSRR = (1 << 1)): (GPIOD->BRR = (1 << 1));

(data & (1 << 2)) ? (GPIOD->BSRR = (1 << 0)): (GPIOD->BRR = (1 << 0));

(data & (1 << 1)) ? (GPIOD->BSRR = (1 << 15 )): (GPIOD->BRR = (1 << 15 ));

(data & (1 << 0)) ? (GPIOD->BSRR = (1 << 14 )): (GPIOD->BRR = (1 << 14 ));

}

u8 GET_DATA()

{

u8 data = 0;

DATALINE_IN();//设置AD0~AD7对应的io为输入

if(GPIO_ReadInputDataBit(GPIOD,GPIO_Pin_14) == 1)

{

data |= 0x01;

}

if(GPIO_ReadInputDataBit(GPIOD,GPIO_Pin_15) == 1)

{

data |= 0x02;

}

if(GPIO_ReadInputDataBit(GPIOD,GPIO_Pin_0) == 1)

{

data |= 0x04;

}

if(GPIO_ReadInputDataBit(GPIOD,GPIO_Pin_1) == 1)

{

data |= 0x08;

}

if(GPIO_ReadInputDataBit(GPIOE,GPIO_Pin_7) == 1)

{

data |= 0x10;

}

if(GPIO_ReadInputDataBit(GPIOE,GPIO_Pin_8) == 1)

{

data |= 0x20;

}

if(GPIO_ReadInputDataBit(GPIOE,GPIO_Pin_9) == 1)

{

data |= 0x40;

}

if(GPIO_ReadInputDataBit(GPIOE,GPIO_Pin_10) == 1)

{

data |= 0x80;

}

return data;

}